• petesergeant 10 days ago
    It's 8 minutes, not one minute

    The people in the study were out of shape to start with

    The improved measures were insulin sensitivity index, peak oxygen uptake, and "skeletal muscle mitochondrial content"

    No change in body mass

    In conclusion, if you're out of shape, you can improve a limited number of fitness measures just as much doing 3x8 minutes of higher intensity exercise as much 3×45m less intense exercise over 12 weeks

    • cycomanic 10 days ago
      While you are somewhat dismissive about the results, they really only confirm many other studies which found that HIT (High intensity training, what is discussed in the article) training achieves the same effects as much longer endurance training at much shorter times. This has been found for both non-athletes and athletes and in fact training for professional endurance athletes has drastically changed in the last 5-10 years (read interviews with e.g. professional cyclists, they train significantly less, but at much higher intensities than 7 years ago, lots of them have observed this transition).

      However, your point about body mass is correct, without making your calorie intake less than your expenditure you will not loose weight. I also recall that there have been some studies that found it might be harder with HIT, because you are hungrier after HIT than low intensity exercise.

      • GatorD42 10 days ago
        Athletes are not training less at higher intensities overall. The dominant paradigm is polarized training - huge amounts of low intensity with small amounts of high intensity mixed in.


        • raspberry1337 10 days ago
          To add further, research has gone further into how intensity and low intensity improves different things - different fibres, genetics, factors of health etc. Heavy lifting affects fibers that are not affected by high-rep medium-low lifting, for example.

          Huberman lab and The Drive podcast that I have listened to have had several academics in this field discuss the divergent effects of different modes of training.

        • trynewideas 10 days ago
          Injury risk plays a part in that, especially for athletes, and is something most SIT/HIIT studies that focus on metabolic impacts don't usually measure: https://www.minervamedica.it/en/journals/sports-med-physical...

          > With particularly high rates of knee and ankle sprains and strains, neuromuscular training and pre-strengthening programs, which have been previously demonstrated to be effective among young athletes, may be particularly worthwhile in prospective participants

        • cycomanic 10 days ago
          You're correct they do polarized training, but the overall times have gone done significantly. This is due to polarized training, i.e. yes when they train long and easy athletes go long and easy, however if there is high intensity training you do relatively short sessions but full on. Importantly the middle ground sessions, where people trained for hours with medium intensity have completely disappeared. Read any interview with an older professional cyclist who experienced the transition, they all mention that they are training significantly less time now.
        • TeMPOraL 10 days ago
          That's interesting. Makes sense for athletes, but unfortunately seems not transferable to non-athletes, simply because hardly anyone has time for "huge amounts of low intensity" training.

          Some people find success in organizing their life to get enough exercise in the natural way, as part of activities of their day, but I think the popularity of HIIT in recent days clearly indicates there's also lots of people who want to optimize for minimum of time spent on exercising. Myself I'm one of such people.

          • sn9 10 days ago
            The question isn't if people have time for elite levels of training.

            The real question is if you can get more done in the time available to you with HIIT or LISS cardio.

            If you're sufficiently time constrained, HIIT will win.

            But past a certain threshhold, LISS will always allow you to perform a greater volume of work with lower recovery costs and lower injury risks and, consequentially, greater benefits to health and fitness.

            • sundvor 9 days ago
              I think you last point is very important.

              For overall health, going for "failure" in weight lifting appears to be the delusional to me; it's much better to lift at a consistent, repeatable level than to greatly increase the risk of injury chasing short term gains. When injured, your volume is going to be zero.

      • sebastianz 10 days ago
        > training achieves the same effects as much longer endurance training at much shorter times

        The HIIT part of their training has a different purpose than the slower part. Each type of training serves a different purpose.

        A lot of discussion currently also revolves around putting more emphasis on "Zone 2 training" with many hours & kms trained at lower intensity, for better endurance and efficiency of slow-twitch fibers.

        > read interviews with e.g. professional cyclists, they train significantly less, but at much higher intensities than 7 years ago

        Do you have any reference for this claim?

        • dropofwill 10 days ago
          Jay Vine recently said in an interview that last year his max hours per week was 30 and that wasn’t training, it was a big week in a grand tour. His coach at least seems to be on a mid 20s hours a week approach.

          Jay implied this was a change throughout the peloton, but you can still see old school strategies doing well (Bernal for example does huge volume in base from strava).

          • oezi 10 days ago
            One key thing to remember is that humans can't do much more than 30 hours per week of exercise because they can't consume sufficient calories to compensate.

            It has come to the point that tweaking nutrition science to feed athletes better so they can train more is a key aspect of the ultra endurance training (e.g. the Norwegian Iron Men around Olaf Alexander Bu).

            • tayo42 10 days ago
              That's 4 hours of activity a day. That can't be true. I do that. I should be fading away then but hover at the same weight.
              • oezi 10 days ago
                4 hours of strenuous exercise. This should consume around 3000 kcals.

                Studies have found that humans cannot consume more calories than 2.5x their basal metabolic rate.

                • petesergeant 9 days ago
                  Do you have the source for this? I tried ChatGPT:

                  >> Someone on the internet wrote "humans cannot consume more calories than 2.5x their basal metabolic rate" -- which study might they be quoting?

                  > I am not aware of a specific study that states that humans cannot consume more calories than 2.5x their basal metabolic rate. Basal metabolic rate (BMR) is the amount of energy a person needs to maintain basic bodily functions such as breathing and digestion, and it can vary greatly depending on factors such as age, sex, and muscle mass. However, the total daily calorie needs of an individual also depend on their level of physical activity and other lifestyle factors. So, it's likely that this statement is a generalization or an over simplification.

                  • oezi 9 days ago

                    "Incorporating data from overfeeding studies, we find evidence for an alimentary energy supply limit in humans of ~2.5× BMR"

                    A good book the topic is Herman Ponzer's "Burn"

                    The main issue seems the surface area of the GI tract.

                    • petesergeant 8 days ago
                      Fascinating, thank you. Apparently this means the most I can gain over Xmas week is 2.45kg, which is reassuring.
                • sasawpg 9 days ago
                  During aerobic training, Nils van den Poel would average 33hrs/week (3x7hr, 2x6hr) roughly at 250W, which will be in the vicinity of 850-900kCal/hr depending on his body's efficiency, likely around 24-25%. That averages to 4250kCal/day when spread across the week. At his size and fitness level, he is probably in the 1800-2000kCal/day range for metabolic basal rate. He aimed for 7000kCal/day during aerobic training and gained 5kg during that summer on purpose. Math seems to add up to me.
                • tayo42 10 days ago
                  You have to misinterpreting something. 2.5x is 4750 calories total. Athletes are eating more then that.
                  • oezi 9 days ago
                    The key insight is that you can eat more, but your body will not consume it.


                    And nobody is saying you can't expend more energy for shorter times. It is just that you can't sustain it over long times because of our metabolic limits.

      • stabbles 10 days ago
        Do you have references for this? My understanding is that low heart rate training is still standard for elite endurance athletes.
        • tonystubblebine 10 days ago
          I actually think there's a bit of a split at the elite level.

          Eliud Kipchoge, WR in marathon, seems to only be doing one hard faster than race pace workout each week. Call that the HIT. The others are slow or race pace. What actually stands out most to me is the specificity of running close to a race pace marathon every week. https://www.sweatelite.co/eliud-kipchoge-a-typical-week-of-t...

          Then on the other end of the spectrum, the Ingebrigsten family of runners seems to put an emphasis on quality. But even though they do more faster running they keep a lid on the intensity to avoid training to exhaustion. It actually reminds me more of the "Grease the Groove" concept where the faster running may be more for neurological reasons. https://www.outsideonline.com/health/running/culture-running...

          Anyway, neither of these two training models seem to have much in common with HIT. The bulk of the workouts are easy intensity and they are both seemingly ware of the dangers of high intensity. That's where injuries come from and so there can't be too much of it.

          • SamoyedFurFluff 10 days ago
            The vast majority of that WR in marathon is doing low intensity long runs every day with only one day dedicated to race pace. That still broadly strikes me as primarily low-intensity training.
            • wooger 8 days ago
              Well, it's polarised training specifically. Either really low, or very intense.
          • seafoam 10 days ago
            the specificity of running close to a race pace marathon every week

            Suspect that this is also for neurological reasons

        • eloff 10 days ago
          Training endurance is likely a very different regimen than training for most types of sports.
        • fsloth 10 days ago
          How many people benefitting from more exercise are elite endurance athletes?
          • PaulHoule 10 days ago
            You might not want to emulate elite endurance athletes in that they get too much of a good thing…. That kind of training puts you at risk of atrial fibrillation.
            • kritiko 10 days ago
              A recent study on this encourages exercise regardless.


              > Conclusion: Although older male endurance athletes experienced an increased risk of AF, the long-term risk of stroke was substantially reduced compared with non-athletes.

              • mattwest 10 days ago
                True, but I think the commentor is referring to the U-shaped relationship of AF and endurance training.

                Higher probability with zero exercise, lowest probability at moderate exercise, but an increase in probability as you enter the extreme territory. In my case, 1000+ hours/year for 8 years led to this outcome

            • mattwest 10 days ago
              PAFIYAMA. Happened to me at 27yo. Thankfully ablation solved the problem and I'm more or less "cured". Interestingly, I had many ectopic beats post-surgery which subsided once I regained my old fitness level.
      • AmericanChopper 10 days ago
        > HIT (High intensity training, what is discussed in the article) training achieves the same effects as much longer endurance training at much shorter times

        Certainly not the same effect. HIT training doesn’t improve respiratory or cardiovascular fitness as effectively as continuous training does, and it doesn’t condition the muscles for endurance as effectively as continuous training does either.

        I don’t know much about cycling, but I know a lot about endurance running, and the typical training regime will utilise continuous training (such as long runs, recovery runs…), as well as high intensity training and some training that’s a mixture of both, like fartleks. The reason being they all produce different results, and you want the benefit of all of them.

        Here’s a video made by Eliud Kipchoge‘s athletics team that talks about the benefit of long runs:


        They have other videos about the other training intensities they use as well. Their training facility is also at a rather high altitude, which is basically its own form of training as well, or a legal form of blood doping, depending on how you look at it.

        • itsoktocry 10 days ago
          >Here’s a video made by Eliud Kipchoge‘s athletics team that talks about the benefit of long runs:

          Is there any science here, or just anecdata from elite athletes, who are often terrible judges of their talent? It's really hard to judge this stuff.

          • this_user 10 days ago
            You can read up on Dr. Stephen Seiler's research (or watch his lectures on YT). He is one of the leading academics in the field of endurance. His results clearly demonstrate that a "polarised" approach with at least 80% low intensity work yields superior results to more high intensity approaches even in athletes who only train for a limited amount of time each week (3-4h).

            That is not to say that HIT doesn't work, and doing something is certainly better than doing nothing in any case, but if you want to maximise the training effect w.r.t. endurance for a given time budget, doing mostly LIT is the better option.

            • logifail 10 days ago
              > He is one of the leading academics in the field of endurance. His results clearly demonstrate that a "polarised" approach with at least 80% low intensity work yields superior results [..]

              (Sorry, I have to ask) but results in what?

              It sounds like there's a risk of focussing on (endurance) athletes, not on unfit sedentary desk workers. Talking about which of the former benefits most from which particular training methodology could be missing the point, which is that it's the latter who are the group who really need to get off our backsides to improve our general health.

              In other words, getting a few extra % of performance out of already fit people is of interest to a minority, but is irrelevant as far as public health policy is concerned.

        • logifail 10 days ago
          > HIT training doesn’t improve respiratory or cardiovascular fitness as effectively as continuous training does, and it doesn’t condition the muscles for endurance as effectively as continuous training does either

          Assuming you're not looking to become an endurance athlete, is conditioning muscles for endurance something one should aim for? Why?

          "Improved cardiometabolic health" sounds like something everyone - including us sedentary workers with families and not much free time - might benefit from. Being able to achieve health improvements in short training sessions would appear to be a really important option.

          • andmarios 10 days ago
            Being able to walk for 3-5km, maybe with a little incline, play with your kids, do a few chores, is important. A 25-30 minute jog every now and then or 10-15 minutes of light cardio/HIIT mixup can help with this, no need to go full endurance.

            Furthermore a more proper fitness regime will fix your posture and improve your quality of life immensely. Things like a flight of stairs, getting in and out of the car, carrying a couple bags of groceries, or just getting up from the floor will become much easier. Again, not going into hours of training, but to 15-30 minutes a few times per week. Your kids can watch. :)

            I don't challenge the research results. Just saying that there are more upsides than just cardiometabolic health, as someone who has seen this first-hand, going from couch potato to a little more active lifestyle.

            • feet 10 days ago
              Training specificity is a thing. Why would endurance training fix your posture?
              • jeltz 10 days ago
                Long distance running certainly puts a load on your back and your shoulders. I have been sore there the day after some really long runs, so I can see how it improves posture. Also you need to focus on proper posture when doing long runs.

                Is it the most time efficient way to fix posture? For sue not, but it should work.

          • AmericanChopper 10 days ago
            If you live an entirely sedentary life then any exercise is an improvement, and if high intensity training has these benefits, then great… but high intensity and continuous absolutely don’t produce the same training outcomes, as the parent comment claims.
          • epistemer 10 days ago
            I do super intense conditioning once a week and walk 5 times a week.

            People that can't be bothered to even walk are not going to stick to intense workouts. It is completely delusional.

            Not to mention, we know these do not train the same energy systems or have the same benefits too.

            This whole discussion is dumb.

            • sasawpg 9 days ago
              I can't be bothered to walk, I drive 3 minutes to a grocery store probably daily. I will drive between the grocery store and convenience store, primarily because I'm lazy but also because it is faster and I value my time. I also ride my bike on average 8-10hrs/week. Not as delusional as you may think.
        • kilgnad 10 days ago
          >Certainly not the same effect. HIT training doesn’t improve respiratory or cardiovascular fitness as effectively as continuous training does, and it doesn’t condition the muscles for endurance as effectively as continuous training does either.

          This is actually incorrect. It's not well known, but the science is actually very clear about this. HIIT is much more effective then long term continuous exercise for VO2 max. This has been shown across Several studies.

          Many coaches and training programs don't incorporate the science into their training regimes. So so called "experts" don't really know. You'll be surprised how ingrained the belief is and it's hard to turn it around if you've been under the belief for years that you need to do long continuous training routines to improve cardio.

          Roger Bannister the first person to clear the 4 minute mile used HIIT exclusively for his training and he's the first person to change the science around this. The myth, however, persists and you still see people plugging in miles and miles into their training routine when HIIT works better.

          • AmericanChopper 10 days ago
            You've misunderstood what VO2 max is. It measures your ability to metabolize oxygen into carbon dioxide, and it measures your pulmonary function, the performance of your heart, the efficiency of capillary delivery and the efficiency of your muscles. You can increase VO2 max by training any component of those systems, and high intensity training only targets certain components of it.

            HIIT doesn't "work better" than continuous training in this respect, it simply targets a different part of the system than continuous training does. For instance if you wanted to increase the stroke volume of your heart (a component of VO2 max), then the scientifically proven best way to do that is with extended aerobic exercise (continuous training).

            VO2 max is also not the only measure of fitness. For example, lactate threshold is an incredibly important factor for distance running, and it is improved by extended periods of training at your lactate threshold (continuous training). Incidentally, you wouldn't be excepted to reach your lactate threshold during a 1 mile run. For even more context, Eliud Kipchoge doesn't have an especially remarkable VO2 max, it's about what you'd expect from any elite athlete. But he does have an absolutely insane lactate threshold.

            Modern endurance training is incredibly science based. That's why if you go and look for a marathon training plan on the internet, even the most basic ones are going to include a mixture of different training intensities, distances and durations. It's also why the athletics team who made that video I posted also have other videos describing the high intensity components of their training regime, and why the members of this athletics team have succeeded in pushing the limits endurance performance much further than they ever have been pushed before.

            If you'd like to take up debunking training myths, I'd suggest you look a little bit further into what VO2 max actually is, and what other types of fitness metrics also exist.

            • kilgnad 9 days ago
              >If you'd like to take up debunking training myths, I'd suggest you look a little bit further into what VO2 max actually is, and what other types of fitness metrics also exist.

              It depends on the level you're looking at. Lower level components compose to form higher level components. For example heart efficiency is one component that composes with others to form VO2 max. Muscle lifting strength is not a a component that makes up for this. Of course I am looking at a higher level metric then you suggest. There's no point in arguing how granular things are. I could turn it around and talk about how the mitochondria and DNA is a component of stroke volume but that's just, again, pointless.

              >HIIT doesn't "work better" than continuous training in this respect, it simply targets a different part of the system than continuous training does. For instance if you wanted to increase the stroke volume of your heart (a component of VO2 max), then the scientifically proven best way to do that is with extended aerobic exercise (continuous training).

              You are incorrect about stroke volume. Recent studies show that cardiovascular and muscular adaptations to HIIT are comparable and sometimes even greater than those of steady-state training. In regards to cardiovascular adaptations, these studies show that HIIT increases stroke volume and VO2max to a greater degree than steady-state cardio (stroke volume: 10% greater improvement; VO2max: 6% greater improvement). These studies also suggest HIIT increases mitochondrial density, which allows us to create more energy, to a similar degree as steady-state but in less time and fewer days per week.

              Sources: https://www.researchgate.net/publication/308600869_High-Inte...

              The above paper shows how VO2 max is increased by HIIT


              The above page shows how VO2 max compared with Continuous training is the same if not better.


              The above is a page on Roger Bannisters training routine. He exclusively did intervals and ran only 5 hours per week to achieve the first 4 minute mile, thereby proving that the most popular and almost exclusive training routine for the time (continuous training) was not as effective as HIIT.

              Nowadays athlete runners regularly blow past the 4 minute limit because interval training is now common place. In fact people in the know... people who train the top athletes know that intervals are the primary training routine to improve VO2 max (and virtually all associated lower level components that influence it, if you want to be pedantic.) So this "myth" I'm "debunking" is mostly a myth among the more amateur athletes (aka people who don't break 4 minute miles). I believe you are likely part of this peer group which is a logical deduction given your incorrect reasoning.

              If you'd like to debunk other people I suggest you cite resources because you are mistaken on this area and if you read the science you would know. Spitting out a lot of technical jargon while making you sound intelligent does not take the place of actual the science and cited sources that serve to prove a point. Thank you.

        • code_runner 10 days ago
          Just to chime in for anyone wondering who Kipchoge is if you don’t follow marathoning.

          He is hands down the best of all time and is totally in a league of his own. He trains constantly. His entire life revolves around it.

          • jeltz 10 days ago
            And last year he got a new world record for marathon at 37. He is the best marathon runner in the world, currently and ever.
      • hutzlibu 10 days ago
        "training achieves the same effects as much longer endurance training at much shorter times. "

        Like other commentors have said, certainly not the same effects, only maybe for the effects tested. High intensity training for example has a much higher risk of injury.

        • jmmcd 10 days ago
          I think it depends - running miles and miles at low intensity will damage my middle-aged knees more than HIT.
          • strken 10 days ago
            With zone 2 training, if you're not that fit you might be able to hit the right intensity just walking fast up a slight incline.
          • jasonladuke0311 10 days ago
            > running miles and miles at low intensity will damage my middle-aged knees more than HIT

            Maybe, maybe not. But running isn't the only method of cardiovascular exercise.

          • wooger 8 days ago
            A common misconception, running isn't bad for your knees, poor form is bad for your knees.
      • karpichoge 10 days ago
        > training for professional endurance athletes has drastically changed in the last 5-10 years

        Not by drastically changing their plans to reduce the hours and do HIIT instead.

        Endurance training is what you do in endurance sports. A long distance runner needs to put in the miles. Hours after hours of running. That's it. Cyclists are on their bike 5+ hours regularly. Rowers do 10 sessions of 2+ hours a week, only few of them at high intensity. It's the hours that bring you the medal.

        In fact, in order to be able to perform those long hours, endurance athletes typically force themselves to keep he intensity down. You can go hard for an hour or two, but then you need a rest day next day. You won't make it to the Olypics on 3-4 sessions a week though. So, you need to be smart and tune the intensity so that after your morning 2h distance piece you can actually meaningfully push some weights in the evening and be fit next morning for the next piece.

        These 10-min HIIT "hacks" may be better for sedentary people than not doing anything at all. But they are not a silver bullet. To get anywhere, you need to put in the hours. No way around that.

        Source: I joined the team that brought my brother to qualify for Rio in an endurance sport.

      • dr_dshiv 10 days ago
        > without making your calorie intake less than your expenditure you will not loose weight.

        I’ve never believed this — only because my weight is so consistent and my eating is not. My body must have a way to regulate the absorption of calories from the gut. When I have some insanely high calorie meal, my body doesn’t necessarily absorb all the calories. This seems easy to measure, so I must be wrong. Or…

        • dahart 10 days ago
          FWIW, I thought the same thing about my body for a long time, most of my life. I have usually been slightly overweight, a bit chubby, but pretty active in terms of sports and outdoor activities and exercise. Then I tried counting calories, and it totally worked, and I realized I’d forever been mentally resisting the idea of budgeting my food. My theory is that my regulating system isn’t gut absorption, it’s just how full I feel, and the threshold where I choose to stop eating, on average. My threshold is slightly higher than what I need to be skinny, and counting calories taught me what it feels like to eat the correct amount for me, which leaves me just a tiny bit hungry. I’m not currently counting calories, and I’m gaining weight little by little. Hard to say what happens when you have a one-off over-eating meal that’s insanely high calorie. You probably don’t absorb all the calories of an abnormally high-calorie meal, but that may change if you always eat a high calorie meal. Under-eating on occasion might have a different effect than over-eating. But yeah, it is easy to measure, if you can bring yourself to do it. I developed mental tricks so that it was easier to count calories and be fine being a little hungry, I feel like it’s important to avoid framing it as a self-control problem, or as overcoming hunger, and find ways to actually want to stick to the budget.
        • smith7018 10 days ago
          I'm not sure what to tell you besides it's true. I did crossfit for years without monitoring my diet and was always disappointed with how little I felt my body changed. I monitored my caloric intake for two months and was shocked to see how much of a difference it made.

          Also, weight gain/loss should be measured on a weekly scale rather than daily. You might feel like your eating isn't consistent but it could be on a weekly-basis. For example, you might barely eat one day but eat 3500 calories the next. That seems like inconsistent dieting but in actuality, they average each other out.

          • SketchySeaBeast 10 days ago
            Yeah, day by day it's not important - how full your bowels and bladder or how much water you're retaining are going to effect you more than your 24 hours of weight loss. It's a waste to sample that often and can be discouraging for no reason. It's really week by week and using that data to calculate a trend.
        • edanm 10 days ago
          > I’ve never believed this — only because my weight is so consistent and my eating is not.

          That's only one side of the equation.

          It is a basically proven fact (and largely implied by physics) that `calorie intake - expenditure = net weight change`. That is pretty much beyond dispute.

          It is also true that some things affect expenditure, and it seems likely that most people have a "set point" that your body attempts to return to. This is also almost certainly changeable, as people have managed to change it in the past. (And this is less surely true than other things known.)

          So yes, it's entirely possible to eat "inconsistently" and not have net weight change, your body is probably subconciously causing you to eat less after you eat large meals, and vice versa. Or possibly causing you to expend more energy after large meals.

          • jcims 10 days ago
            Could also be that the incredibly complex digestive system isn't just a food mulcher but is capable of moderating caloric intake based on any number of parameters.
            • caeril 10 days ago
              Eat a high-fat meal or a can of Pringles with Orlistat, then you'll have an idea of what happens if your digestive system fails to extract calories from what you eat. Trust me, you'll know.

              No, our digestive tracts are extremely good at extracting any and all usable calories from our food.

              100% of the time, when someone makes this claim, they are mis-estimating either their intake or expenditure, or not tracking for a long enough time period to escape the error bars inherent in daily hydration variance.

              • jcims 10 days ago
                Best I can do is 95%.
          • joyeuse6701 10 days ago
            How easily one can lose weight seems to be more than calories in and calories out. Women with PCOS struggle mightily with weight. Having said that, I'm sure if you put a person in a box for 21 days without food you will observe a net weight change, but I'm sure the speed at which weightloss occurs or is observed will include other factors beyond calories in and out.
            • asdff 10 days ago
              The Alone show is pretty interesting as an example of what could happen being in a box with no food. Men and women of all shapes and sizes go into that show and they all just slough off weight, like over a pound a day sometimes, and struggle bringing in enough food for their body to not starve. Many are medically discharged from the show if they lose too much weight too fast where it puts their internal organs at risk.
            • wooger 8 days ago
              There's a psychological component to sticking to a diet for sure, but no, a calorie deficit of the same amount will result in the same weight loss rate.

              People locked in a box will not be able to cheat and will demonstrate this.

        • gassiss 10 days ago
          if your weight didn't change, most likely you were eating at maintenance. The fact that you have a surplus every now and then won't change your body composition. Consistency matters a lot with regards to human weight.

          To add to what someone else said, you probably ate below your threshold to be able to maintain your weight. You can't guess this, the only way to get an accurate ESTIMATE on how much you actually ate in calories is to measure. Even pros over/under estimate what they eat in terms of calories

        • grogenaut 10 days ago
          It's pretty easy to come up with ways the body wouldn't take up calories. I and everyone here has had diarrhea for example. I've eaten 5k calories on a sedentary day with no impact on weight as well tho it's hard to account for water without a strict accounting.

          What's harder to refute is the loss of weight due to calorie restriction which is mostly physics. This is what the gp is talking about.

        • staplung 10 days ago
          The NYTimes just ran an article about nutrition myths. One of them was about calories in - calories out.

          “ Ultraprocessed foods — such as refined starchy snacks, cereals, crackers, energy bars, baked goods, sodas and sweets — can be particularly harmful for weight gain, as they are rapidly digested and flood the bloodstream with glucose, fructose and amino acids, which are converted to fat by the liver.”

          • snowwrestler 10 days ago
            Your body will only store surplus fat long-term if you consume enough calories to maintain the surplus. Otherwise your body makes fat from the sugary sweets, but then later converts it back and burns it when you need energy.

            The real “myth” of calories in = calories out is that it’s possible to do it by feel. It takes a lot of work and math, like spreadsheet-level, to actually track calories in and out. So even though it is physically true as a concept, it’s not a good weight management strategy for most people.

            Sugary snacks don’t make you feel very full for their caloric content. So unless you’re literally writing down the caloric information on the wrapper and comparing it to your total daily activity, it’s easy to overeat.

            • dxhdr 10 days ago
              > The real “myth” of calories in = calories out is that it’s possible to do it by feel. It takes a lot of work and math, like spreadsheet-level, to actually track calories in and out. So even though it is physically true as a concept, it’s not a good weight management strategy for most people.

              The real myth is that you can track calories in and calories out.

              How do you measure how many calories your body absorbs from the food you eat?

              How do you measure your calories out, particularly your resting metabolic rate?

              Here's a hint -- the body changes its resting metabolic rate in response to calories in! Probably! Unless you eat junk food, and then maybe it doesn't!

              • asdff 10 days ago
                You don't need to know these rates, you just need to have a point of reference from which you can change according to your weight loss goals. Not losing enough weight for the given caloric intake? Then just dial it back and reassess.
              • snowwrestler 10 days ago
                It is absolutely possible to do it. Thousands of athletes and artists who depend on their weight professionally do it. Here’s one example:


                It does require work to understand your particular body, and discipline to do it consistently. Which is again, why it is not a good technique for most people. Most people don’t have the time, motivation, or really the need to do what this woman (in the video) is doing.

              • dahart 10 days ago
                It’s really common for the argument against CICO to be that it’s not perfect, measuring input and measuring output seem hard, and metabolism is elastic, and people are different. Those things are all true, but using CICO in practice to lose weight actually works, and it’s quite effective for most people, as long as you actually do it. CICO is how bodybuilding and modeling works. ;) The hardest part isn’t the measuring. The hardest part is making it a habit.

                One secret about using CICO is that you do not need to know the gut absorption rate! You just need to track the calories before absorption, the numbers printed on the box. Easy these days with a smartphone app. The measurement does not need to be perfect at all. It only has to be decent on average. You can have variable accuracy of 25% on any given food and still get well under 10% on average for a week. It doesn’t matter if there’s a bias either, if you track your weight. The reason absorption and bias don’t matter is because you’re doing science with a black-box (your body). Measure the known input, monitor the output. Do it for a long time and you’ll find the maintenance input. Track input above that and verify mass gain, track below and verify loss. The maintenance value you come up with will “absorb” and bias, and gut calorie conversion rate, and other inaccuracies.

                Measuring output is easy with a heart rate monitor. Changing metabolism we already discussed, but important to know that the range of elasticity is like around 15%, and in practice for any give person may be lower. It’s not some massive factor you can’t predict, it’s within a narrow enough range for the majority of people, statistically, that you don’t need to worry too much. And it will be accounted for if you track calories and weight over a long enough time frame.

              • evandale 10 days ago
                You track calories in by making all your food and weighing everything you eat.

                In practise you don't need to track the out because it doesn't change much per day. It's not easy to burn 200 calories but it's easy to consume them. That's why it's common to hear that weight loss happens in the kitchen.

              • substation13 4 days ago
                Smartwatch can give a reasonable approximation of calories out
              • sn9 10 days ago
                Tracking actually makes this super simple to account for.

                Apps like Macrofactor do it for you. You just track what you eat and your weight.

          • dr_dshiv 10 days ago
            Here's a Harvard fluff piece making the same "myth" claim: https://www.health.harvard.edu/staying-healthy/stop-counting....

            And here is a recent peer-reviewed article that summarizes the debate: Ludwig, D. S., Apovian, C. M., Aronne, L. J., Astrup, A., Cantley, L. C., Ebbeling, C. B., ... & Friedman, M. I. (2022). Competing paradigms of obesity pathogenesis: energy balance versus carbohydrate-insulin models. European journal of clinical nutrition, 76(9), 1209-1221.

          • wooger 8 days ago
            I guarantee the skinny long distance runners and pro cyclists you see all pound far more ultra processed pure sugar than anyone fat you know. It's literally the only way to take in calories fast enough to keep exercising at an intense level for hours.

            Regardless of diet you will lose weight if you eat fewer calories than your body is burning. It will be harder if you eat junk food, but quite possible.

        • pengaru 10 days ago
          Availability of the calories varies substantially, and day-to-day water retained varies on the order of a few lbs easily.

          Just consider how much flatulence varies meal-to-meal, that's largely produced by calories guests living in your gut "burned" instead of you.

          The trouble is it's a complex ecosystem hosting many lives, controlled by hormonal knobs affecting behavior/activity-level and energy storage, and the makeup of the food hugely affects how much is absorbed and at what rate.

          Everyone knows firsthand when over-eating a massive meal of hard to digest foods there's a substantial amount of energy deposited in the toilet... And wild pigs / pet dogs don't get excited about eating human feces for lack of caloric value.

          It's just an upper bound, nothing more.

        • gnad_sucks 10 days ago
          There's a lot of truth in what you're saying. But maybe they use calorie intake to mean "calories actually absorbed by your body", and not "calories present in the food you put into your mouth"? Just generally speaking it would be difficult to believe that calory absorption doesn't depend on anything.
      • smeagull 10 days ago
        > without making your calorie intake less than your expenditure you will not loose weight.

        There are drugs that say otherwise. As a side effect of medication, I've had to increase my calorie intake to maintain my weight.

        Not to mention the relative bio-availability of foods differs even when their calories don't. Fats and Proteins need more processing per calorie than Carbohydrates.

        I'm also fairly certain there are limits to the human bodies ability to absorb calories. i.e. you could saturate your diet by eating way too many calories, but your eventual weight gain would be at the limit of your body's ability to store fat.

        • 988747 10 days ago
          > As a side effect of medication, I've had to increase my calorie intake to maintain my weight.

          Is it a medication that increases energy expenditure? Something that boosts your metabolism?

      • throw1234651234 10 days ago
        They are correctly dismissive - you won't run a 5k from 3x8mins a week. Nor will you deadlift 500 lbs. Nor will you get a good sport.

        It's a good tidbit for "something is better than nothing", but no more than that.

        • logicchains 10 days ago
          >Nor will you deadlift 500 lbs

          Maybe not 500lbs but somebody could certainly eventually deadlift 400lbs from 3x8 minutes once a week, as long as they keep it intense and keep increasing the weight. I say that as someone who can deadlift more than 400lbs after many years of practicing around 30 minutes/week. If you're lifting hard, a week is barely enough time for the body to recover anyway.

          • throw1234651234 10 days ago
            1. You are not counting warm up. 2. You are not counting specialization? What, do you just dl? What about bench,row,squat,ohp,PU? 3. What about stretching and other maintenance? 4. Diet, sleep, etc.

            I believe you, but you are really confusing people who don't know what it takes like the poster above.

        • jeltz 10 days ago
          Aside: Running a 5k is something some people can do without any training at all. I ran about 5 km without stopping the second time I ran after 10 years of inactivity and I am sure I could have done it the first time too if I had really wanted to. A more reasonable challenge would be to run a 20 minute 5k. I feel that is roughly equivalent to dead lifting 500 lbs.
          • throw1234651234 10 days ago
            A reasonable challenge would be to run a 24 minute (8min/mile) 5k without falling apart in the next two days. Most people cannot run 3 miles at a 9 minute pace consistently. This is assuming low BMI.

            "I feel that is roughly equivalent to dead lifting 500 lbs."

            It is and it's not. No one naturally deadlifts 500lbs. Maybe 315, maybe. 500lbs is 3+ years of training. Most won't ever hit it even after 10. (Diet, sleep, injuries). A lot of 10 year olds can run 6min miles due to low bw though. It's two completely different standards.

            With that said, you are absolute underrating the difficulty of both.

      • n8henrie 10 days ago
        If you have references handy I'd love to read more. Specifically, it sounds you're saying that there is evidence in recreationally trained athletes that less frequent HIIT improves [meaningful outcomes] equal to much longer and more frequent training durations of moderate intensity cardio.

        I'm much more familiar with the evidence on strength training, where it seems that volume and intensity both have important roles. But at this point in my life, I no longer have the time to train as often as I'd like!

      • derrida 10 days ago
        > they really only confirm many other studies which found that HIT (High intensity training, what is discussed in the article) training achieves the same effects as much longer endurance training at much shorter times.

        Show me 1 conventionally conceived of "endurance athlete" amateur mid of the pack or professional who has adapted this? Marathon, Iron man etc. Just 1. I'd love to see if anyone got a result in a marathon etc that was like a pb or close to a pb this way. I highly doubt.

      • waynenilsen 10 days ago
        I would also add that hit has a better chance of improving overall metabolic health raising resting metabolic rate and allowing you to eat more in the long run. Short run, low and slow will increase total daily expected expenditure but hit is a better long term investment.
        • waboremo 10 days ago
          Eating more in the long run doesn't seem like a better long term investment, especially when eating more for a lot of people results in making less optimal food choices and in turn bad habits. These bad habits can become exponentially bad as you age and start facing a lot of challenging events.
      • jjtheblunt 10 days ago
        > without making your calorie intake less than your expenditure you will not loose weight.

        you could with tapeworms!


      • dmix 10 days ago
        > without making your calorie intake less than your expenditure you will not loose weight

        I've asked on HN a couple times in the past for citations that support this meme and haven't yet found a good source on this. The connection between caloric restriction and weight loss isn't as straight forward as people seem to think, despite that being the standard correlation pushed since the 1950s.

        Calories seems to be the catchall metric pushed around, but it seems to be as much about what you eat, not just eating less. Although I'm sure asking someone to simply "eat less" would still ultimately contribute to weight loss. Whether calories is the thing that matters is the question.

        • tarsinge 10 days ago
          This is not a meme but basic physics. This is how you do your cut and bulk cycles to lose and gain exactly a planned amount of weight. My base energy expenditure is relatively low at around 1800 kcal. If I eat 2000 kcal I will gain around 1 kg in 35 days (1 kg of fat is a 7000 kcal surplus), and similarly I could lose 1 by eating 1600 kcal. For finding sources look up "TDEE".

          Weight loss is complicated because of the added dimension of satiety. If I eat proteins, vegetables and fats without counting I'll be around my baseline. But with sugar and carbs it's impossible to not overshoot without being terribly hungry. Also with less insulin sensitivity found in obese/pre-diabetics people, ingested food can not be efficiently used and end up stored, leading to the vicious cycle of being tired and still hungry.

          • FatActor 10 days ago
            Who generated the heat that you measured in the calorimeter?

            Gut biome bacteria consumed an amount of those calories. How many? It varies from person to person.

            So calories in = calories out, but we don't know how many were used by the person, how many by the gut flora, and how many were excreted do to inability to metabolize. Ergo, hardly basic physics.

            Reductionism is only useful if you know how to apply it.

            • asdff 10 days ago
              You don't need to know all of these things if you are measuring input (calories in) and your output (weight on the scale every week). It hardly matters then how efficient your gut is. These are all relative values. Of course 2000 calories will look different for different people. What matters is if you have an understanding of how much calories you are putting into your system, you can now make changes and measure a response, like cutting down some calories and seeing how that affects your weight over a few weeks or months. You don't need to know all of these rates to do that.
              • FatActor 10 days ago
                I agree with that, as do most people. What I object to is that calories-in-calories-out is the ONLY thing at play, and people claiming "simple physics" are working against any deeper understanding of the issues. I think this side of the argument is "Just eat less and you won't be fat. Duh." What they don't understand is that if a body has a hormonal anomaly, it might need to 5000 kcal/day just meet the 1500kc/day basic metabolic rate because the other 2500 kcal is being metabolized into fat by a broken endocrine system. If they drop down to 1500 kcal/day, only 300kc of that is going towards keeping the body running. It is completely out of their control how the calories are used due to their bodies, so CIn=COut is meaningless. The obesity epidemic is not completely about eating too much (which is part of it), but is about the environmental factors impacting how bodies actually work. If it was just Cin/Cout, gastric bypass would solve the problem, but that is not available to people that are suffering such hormonal disruptions because they would just die or be eating nonstop.
                • sn9 10 days ago
                  More is more and less is less.

                  If this wasn't the case, you'd have discovered a solution to famine.

                  And gastric bypasses are one of the most effective interventions available for people with such disorderd eating that lifestyle changes can't stick.

                  • FatActor 10 days ago
                    Again, black and white thinking doesn't solve the problem. It just alienates people, and sometimes worse.
                    • sn9 10 days ago
                      I have no idea what you're trying to say.

                      It is an objective fact that caloric surpluses and deficits are fundamental to manipulating bodyweight.

                      Any solution will be about getting people to maintain a surplus or deficit long enough to reach their goal weight.

                      There are many ways to communicate that to people, but pretending or trying to convince others that it isn't true is factually incorrect and literally counter-productive to their goals.

                      • FatActor 9 days ago
                        You keep saying less is less more is more. That's a truism which is completely orthogonal to the point, yet you seem to be hung up on it to the exclusion of everything else every other commenter has said to you. Consider that just for a moment.
                        • hungryforcodes 9 days ago
                          No its not. CICO, it's that simple. I'll get down voted by the fanatics that say it's more complicated, but it's not. Eat less and exercise more and you will loose weight. A gastric bypass is just a extreme form of this. You cannot avoid the laws of physics.
                          • FatActor 8 days ago
                            There's a reason your being down-voted, and its not a hive mind, or a conspiracy, or a personal grudge against you. That's simply what it is like to be "wrong". Saying what you said is just playing the victim card.
                            • hungryforcodes 4 days ago
                              I'm not a victim don't worry. I have no interest in being right -- though that you think I'm playing a victim card plays into all the people that deny CICO.

                              But it's ok. I loose weight by exercising and eating less. Like the climate change denialists, you can lead people down the dark path if you like.

                              Me I'll stick with me 3kg loss of weight every month and celebrate.

                        • sn9 8 days ago
                          It's because people are talking about all sorts of irrelevant stuff that has no effect on what one has to do to manipulate their weight.

                          It's missing the forest for the chlorophyll.

          • mister_mister 10 days ago
            The body is not closed system if it would be perfect close system then eating once a day or once per week would have the same effect spreading that over the day. The cells do not use calories. They use ATP, converted different pathways such as glucose, fatty acids, ketones and oxygen.

            Calories are measured by burning them, so that means we are using two different measurements that may overlap but are not compatible.

            In the Calories model would it be possible to explain why people with diabetics type 1, that don't use insulin stay thin even though they would eat massive amounts?


            • tarsinge 10 days ago
              Eating once a day indeed has nearly the same effect. Once a week is not possible due to physical limits of processing that volume of food.

              It's easy to explain your example with diabetics: very simply insulin is what allow muscle to use glucose, but also what stop the body from using its fat reserves. From your link:

              > Desperate to stop its cells from starving, her body had released hormones that, in turn, released byproducts called ketones that turned her blood acidic. If she had not been rushed to the emergency room, she would have died.

              This is similar to the effect of a ketogenic diet, when you avoid eating carbs to avoid insulin secretion, forcing the body to convert the fat reserves to provide glucose for the cells. Diabetics type 1 don't produce insulin, so they just skip insulin shoots to stay in that "mode" but it has obviously other serious health side-effects for them as discussed in that article.

              Also individuals are not the same, there is a lot of variation in TDEE (genetics, health, weight, insulin sensitivity, metabolism, ...). But once you have figured the TDEE for an individual, calorie counting becomes very accurate. Just from the fitness community there is an overwhelming body of research and evidence: https://sci-fit.net/bulking-deficit-gaining/. If you are in calorie deficit, you lose weight. If you are in a surplus, you gain.

              • mister_mister 10 days ago
                The question how do we explain why people without insulin are able to stay thin, while eating massive amounts of calories with the CICO model. Because that case is breaking the model.

                Since your stating that eating once a day is the same as eating once a day. Would you have any sources for that claim?

                Did you know there is allot of research going into the effects of intermittent fasting[0]?

                If you would search for OMAD (one meal a day) on google or reddit you would see that that statement does not hold. There are many changes because blood sugar will stay stable during the day. Nor will there be insulin spikes. There are health startups starting just for stable glucose levels and the health benefits by using continuous glucose monitors[1].

                They already attracted many from the health and longevity communities. It's also possible not to use their product by just eating once a day.

                [0]https://www.hopkinsmedicine.org/health/wellness-and-preventi... [1]https://www.levelshealth.com/

                • Frost1x 10 days ago
                  >The question how do we explain why people without insulin are able to stay thin, while eating massive amounts of calories with the CICO model. Because that case is breaking the model.

                  To my knowledge this doesn't break the CICO model. The disease (e.g. type 1 diabetes) reduces or eliminates production of insulin which triggers metabolism of glucose. Since you're metabolizing less (or no) glucose, you're not gaining as much energy and passing most all that out through waste.

                  If you have a disease you need to consider that your energy expenditure isn't inherently going to be the same as studies estimating from healthy individuals. This doesn't break the model, it just means your intake and expenditure are different than most healthy individuals. People with hypothyroidism have similar issues. Is the CICO model great for these people? If you account for such factors the underlying principles should hold true.

                  • mister_mister 10 days ago
                    I'm afraid that is incorrect, type 1 diabetes still have glucose metabolism, with diabetes type 2 glucose metabolism could be impaired but with type 1 that is not the case.

                    What has changed is that without insulin glucose will stay in their blood damaging organs and veins.

                    Insulin signals to cells take up glucose and other nutrients, first organs like the liver, then the muscles.

                    More information in the link from healthline. https://www.healthline.com/health/diabetes/insulin-effects-o...

                  • jonnycoder 10 days ago
                    You just proved his point. If two people eat 10,000 calories and the one with type 1 diabetes is passing most of it as waste but the other person is storing that in the form of glucose and fat, then CICO is broken in that example. But like you say, account for such factors and the principles hold true; how do we know there aren't factors yet to be discovered?
                    • Frost1x 10 days ago
                      How does this proove the point? In the example given, the diabetic is expending more calories (through waste) than the non-diabetic... the model still holds valid. The diabetic has less net calories absorbed by their body.

                      >how do we know there aren't factors yet to be discovered?

                      We don't and can't (by definition), that's part of the scientific process. Part of that process requires us to find evidence to the contrary or provide a viable testable competing argument. We don't just waive our hands in the air and claim magic gremlins are making people skinny or fat since there are likely limits to human understanding and knowledge, especially at any given specific point on time.

                      Most the evidence out there, that I'm aware of, vehemently supports the CICO model and it makes sense as a complex system resting up very well studied chemical and physical phenomena. The only thing broken seems to be a general understanding of the model being discussed.

                      • librish 10 days ago
                        The point is that when people say calories IN they normally refer to what you put in your mouth, not how much your body absorbs.
                        • mister_mister 10 days ago
                          That is problem with CICO proponents start with scientific terms. But it always ends up with magic what does or does not count based and whatever the argument they are in. CICO models doesn't state anything they claim, but it in the end it's argument into nothing. Because human cells does not use calories it uses ATP through the kerb cycle. That whole process so bizarre complex, and then also based on so many confounded factors, that CICO is just too simplistic and it's almost impossible to lose weight and keep it off according to the model. Link to study about how the biggest losers contestants are doing after the show. Hint not well...


                    • laserlight 10 days ago
                      I find this interpretation of “calories in” very uncharitable. We certainly don't argue over whether eating coal makes one fat. Coal has lots of calories, but we're interested in metabolically available ones. If type 1 diabetes people cannot metabolize glucose, then it doesn't count as in.
                      • mister_mister 10 days ago
                        They do have glucose metabolism[0], but that is the issue with CICO model already you have to start making extra rules about what is digestable and what is not. Calories doesn't state that all. Offcourse it wouldn't because the Calories concept was made for steam engines in 1800's.[1] Not that is matter from when it is. But maybe it's time for new ideas that do explain that conundrum of those type 1 diabetics. The Carbohydrate-Insulin Model of Obesity[2] does have a explanation.




                        • laserlight 10 days ago
                          > extra rules about what is digestable and what is not. Calories doesn't state that all.

                          I wouldn't call those rules “extra”. After all, we're talking about human metabolism and what is digestible or not is central. The calories we're talking about under this topic has nothing to do with steam engines, except that both steam engines and humans take some input, called calories.

                          I don't see any conundrum with type 1 diabetes. They might have a different metabolism that counts differently which calories are in.

                          By the way, do you have a reference for this claim of yours [0]:

                          > people without insulin are able to stay thin, while eating massive amounts of calories

                          [0] https://news.ycombinator.com/item?id=34518288

                          • mister_mister 10 days ago
                            So how do we calculate Calories In and Out according to you? Becausr it sounds like that we have to deal with real world that really complex digestion, hormones, gut biome. You just start adding and subtracting numbers.

                            At that moment CICO dies, because you won't be able to measure anything and just have black box which you give whatever number makes sense in the end.

                            Not that it matters because the cells in human body use ATP not calories. As such calories are at best a proxy for how much food.

                            But that is issue with CICO, it's like magic box and we only have to count IN, as much at what makes the calculation correct later on, also with OUT. That is not very scientific. Because we are unable to reproduce anything.

                            I have posted the article before, have you read it? https://www.everydayhealth.com/eating-disorders/diabulimia/

                            • laserlight 10 days ago
                              A model being difficult or tedious to quantify doesn't make it false. And, all models are wrong, but some are useful.

                              > But that is issue with CICO, it's like magic box and we only have to count IN, as much at what makes the calculation correct later on, also with OUT. That is not very scientific.

                              The whole physics is a magic box. We find qualities of materials after we measure them, because that's how the model is constructed.

                              Let's say that I have a model called mass in volume out (MIVO). It states that mass of a liquid predicts its volume. We measure how much volume a certain amount of water takes, vary the amount, see if the model works, and it does. But a MIVO-denier is not happy, because our measurements with water doesn't reproduce with mercury. Well, duh, because they have different densities. MIVO-denier is still not satisfied, because now they have to go through the tedious task of finding the density of the material they have to work with before being able to apply the model. Furthermore, they have to keep the temperature constant, not mix liquids, etc. Yet, MIVO works regardless of how difficult it is to quantify, measure, or use.

                              PS: Thanks for the reference. I had missed it.

                              • mister_mister 10 days ago
                                > A model being difficult or tedious to quantify doesn't make it false. And, all models are wrong, but some are useful.

                                Here is a link from Harvard saying to stop counting calories[0]. Here is another link from Havard[1] going over the contestants of the biggest loser and how they are doing now.

                                There is new model The Carbohydrate-Insulin Model of Obesity[2] which has explanation that does explain the edge cases CICO is missing.

                                But calories are measuring food, and at the moment there is no better way to have overview of how much across different types of food. But CICO itself doesn't help with long term weight loss.




                                • laserlight 9 days ago
                                  I understand that by quoting my reply on usefulness, you claim that “calories in, calories out” model is not useful. For the model to not be useful, one should prove that people gain weight while consuming a caloric deficit, or that people lose weight while consuming a caloric surplus.

                                  I don't see how these references show that. They are irrelevant to our discussion. The first Harvard piece is bullshit, written for those feel-good types who don't want to put in the effort of losing weight. The second one has nothing to do with “calories in, calories out”. It just states some observation on contestants. The paper has “calories in, calories out” in the title, yet doesn't talk about the model at all. It talks about something else, called conventional model.

                                  Nowhere in “calories in, calories out” I understand that it is easy to create deficit by eating junk food or that one can go back to their old lifestyle once they have lost weight. People fight with an imaginary enemy.

                                  I think that I've explained my view as well as I could. Thanks for your participation.

                                  • mister_mister 9 days ago
                                    Thank you, for at least reading the sources:) At this moment you'll be aware that are other ideas out there. To explain the link with biggest loser, the show used CICO model for the contestants to lose weight. And they did lose weight, So that would suggest CICO is working. But there was follow up and almost all contestants got their original weight back, and others could only eat 1200 calories in a day, that's unsustainable.
                            • sn9 10 days ago
                              You have several misunderstandings of basic science.

                              "Calories" are simply a unit of energy. The energy released by the utilization of ATP can be measured in any unit of measure you like for energy. It won't change the fact that the unit can be calories.

                              This is like arguing about Celsius vs some other unit.

                              Likewise, the CICO model has been replicated over and over again in high quality studies that don't rely on self-reported intake. And this model and information are used by thousands of people every year to manipulate their bodyweight and composition at will in sports like bodybuilding or ones with weight classes.

                              Indeed, treating the body as a black box makes this even easier as tracking caloric intake and your bodyweight is sufficient to do this and apps like Macrofactor do all the math for you.

                              • mister_mister 10 days ago
                                > "This idea of 'a calorie in and a calorie out' when it comes to weight loss is not only antiquated, it's just wrong,"[0] Link from havard.

                                You are under the incorrect understanding that human body is closed system. Food doesn't need to be digested and what is digested doesn't need to be stored in fat cells.

                                Question if you would eat all the food once a week would it have the same effect? Because in a closed system it would, you can fuel the car little by little each day or fill the whole tank. But after one week of fasting they body will respond much different, a person can even die of even trying that scenario [1]

                                Did anyone lose 5 kilo by switching to a light product?

                                But the issue at hand was why people without insulin can eat massive amounts of food but won't gain any weight? Can't explain that with CICO, you can with other models[2].

                                > "Calories" are simply a unit of energy. The energy released by the utilization of ATP can be measured in any unit of measure you like for energy. It won't change the fact that the unit can be calories.

                                This statement is not correct, Calories is burning food. While metabolism goes through absolutely complex system. Kerb cycle, where glucose, ketones, fatty-acids and oxygen are turned in ATP, Link is only 1 small part and doesn't even cover how food was digested before that, by the gut biom, stomach acids. [3]

                                Human metabolism is too complex to discuss here in the comments.





                                • sn9 10 days ago
                                  I have a literal degree in biology and have been reading about physiology, health and fitness, and related topics for well over a decade.

                                  You have no idea what you're talking about.

                                  This is textbook level stuff and you clearly haven't read a single one. Your wiki level understanding is missing the forest for the chlorophyll.

                                  • mister_mister 9 days ago
                                    Would it be possible to at least look at the sources and argue against them? A appeal to authority, and an Ad hominem won't help the discussion along.
                                    • sn9 8 days ago
                                      Would you bother reading the textbooks worth of information I've consumed first?

                                      You aren't entitled to another person's time and effort when you've decided your googling is in any way comparable to literal years of study in environments where you actually get feedback on your understanding.

                                      • mister_mister 8 days ago
                                        > "This idea of 'a calorie in and a calorie out' when it comes to weight loss is not only antiquated, it's just wrong,"[0]

                                        Would it be possible to share sources of the claims that you're making? Instead of demanding them and not reading them when they are presented.

                                        There is no reason for those Ad hominem attacks. We can have civil disagreement.


                                        • sn9 8 days ago
                                          These aren't ad hominem attacks.

                                          I explained to you that you have fundamental misunderstandings so vast in scope that it would take several hours to explain them to you. This criticism was rooted in years of education and research that can't be compressed into a single comment.

                                          If you google things to confirm your worldview, you will get the evidence you wish.

                                          If you wish to see how those who successfully manipulate their body composition at will down to the pound, you would look to those populations who do so like bodybuilders and strength athletes and those who compete in weight classes.

                                          And if you wished to have the ability to discern when an argument is irrelevant or outright wrong, to understand the most basic elements of physiology and physics and chemistry, you would put in the time to read the textbooks which are explicitly designed to convey this information to you in a comprehensive way designed for understanding rather than relying on university PR pieces.

                • snowwrestler 10 days ago
                  You can’t break the “model” as it is basic thermodynamics.

                  If a diabetic is consuming many calories but also excreting many calories, that is still calories in and calories out.

                  • mister_mister 10 days ago
                    That's the point it will not lead to weight gain. But according to CICO they should become fat, but they won't. And if this is possible by not having one hormone. That is quite a big discovery. The human body is way more complex then one hormone. And fat gain can be due to many reasons, another hormone could be cortisol, bad sleep, Obesogens[0].

                    If CICO does not factor in what is not stored or digested. Therefor it's a flawed model. Therefor it would be better to look at what is working, and wath was working before we got unto the low fat craze. In the 1950 up to 1980 bodybuilders where eating low carb high protein diets. Everyone was thin back then, just now we are returning to knowlegde.

                    But the thing is according to latest science obesity the focus is not on CICO anymore. Would be great if more people would be willing to conduct their own N=1 studies and try low carb dieet, keto, or intermittent fasting. It works the same way by keeping insulin low. It might do wonders.



                  • Ar-Curunir 10 days ago
                    Pooping out excess calories is not usually what people mean by “calories out” in CICO
                    • snowwrestler 10 days ago
                      Right, because excreted calories are typically consistently small for most people.

                      That’s not necessarily true for diabetics, so someone with that condition will have a different experience with it.

                      • mister_mister 10 days ago
                        And the reason is only the missing of one hormone, and fat cells won't store energy. The opposite also true, there are people with too much insulin that will gain allot weight.

                        > Despite intensive research, the causes of the obesity epidemic remain incompletely understood and conventional calorie-restricted diets continue to lack long-term efficacy.


                        • snowwrestler 9 days ago
                          “Get diabetes” is certainly a novel approach to a weight-loss plan, I’ll give you that.
                • goodpoint 10 days ago
                  *a lot
              • watwut 10 days ago
                Eating once a day does not have the same effect on your body as spreading the food into multiple portions. And that has different effect then eating the same amount constantly.

                If you will eat once a week, you will dispose of calories you did not absorbed. And you will be starwing by the end of the week, making you passive, weak and tired.

                • mister_mister 10 days ago
                  yup, Someone might even die because of refeeding syndrome.[0]

                  Continuing on your point the body is there not a closed system as defined as:

                  > In a closed system, no mass may be transferred in or out of the system boundaries. The system always contains the same amount of matter, but (sensible) heat and (boundary) work can be exchanged across the boundary of the system. Whether a system can exchange heat, work, or both is dependent on the property of its boundary. [1]

                  [0]https://en.wikipedia.org/wiki/Refeeding_syndrome [1]https://en.wikipedia.org/wiki/Closed_system

          • elenaferrantes 10 days ago
            How do one manage to eat exactly the amount of calories one consumes ? Based on the calories in/out weight gain theory a little error of 50 calories/day would lead to 50*365=18250 extra calories/year ie 18250/9000=~2kg of fat. 20kg in 10 years ! Eat an apple a day and you’ll be massively obese in few years.
            • sn9 10 days ago
              It just has to average out in the long term.

              No one eats the exact same thing everyday.

              And you can eat less or more throughout the year.

              You've never had a holiday feast?

              • elenaferrantes 9 days ago
                That’s my point. Regarding people that maintain the same weight, I highly doubt they eat on average the _exact_ amount needed. There must be physiological adjustments that are broken in some people.
                • sn9 8 days ago
                  That's not necessary at all.

                  People who maintain the same weight simply eat their maintenance calories on average over the long term.

                  That's just how averages work.

                  I feel like you have some kinda fundamental misunderstanding of something to not understand this, but I don't know what it could be.

            • asdff 10 days ago
              Just use a sensible buffer or add in some extra cardio.
          • acuozzo 10 days ago
            > This is not a meme but basic physics.

            The issue is: How are we defining calories IN?

            Consider the extreme example of having a parasitic worm living in your digestive system. Is IN == [food passing mouth] or is IN == [food not being ingested by worm(s)]?

            Now consider "normal" digestive flora. How are we defining IN here?

            • asdff 10 days ago
              All of that doesn't matter. Calories in just serves as a reference point for you to see how much you are actually eating. Then you can make changes to calories in, and see results on the scale. Sure everyone is at different efficiencies, that doesn't matter though. You are basically putting in less gas in the tank; that's going to make a hybrid and a gas hog both go for less miles than what a full tank would do.
              • acuozzo 8 days ago
                You're not addressing the following in your analogy which can have a significant impact on CICO if IN==passes_mouth.

                1. Having a hole in your gas tank (parasite(s) e.g. a tapeworm)

                2. Having a modification to your fuel tank to convert ethanol into octane (non-parasitic digestive microorganisms a.k.a. "gut flora")

            • gassiss 10 days ago
              you're technically right, but just nitpicking. Of course you could count the calories in fibers and that wouldn't make you fat, as your body can't process that. But most people do not eat fiber for 90% of their meals
              • acuozzo 10 days ago
                > you're technically right, but just nitpicking

                I was hinting at something bigger than just a nitpick. I'm hypothesizing that gut flora interfere with macronutrient ingestion in a statistically significant way.

                Microorganisms exist which produce glucose from materials that, if ingested by a human, would be emitted as waste.

                What if colonies of these microorganisms were present in the human gut and unevenly distributed in the population?

              • lukeschlather 10 days ago
                People often switch from more processed grains to whole grains specifically to increase their fiber intake and reduce the processable calories they're ingesting. I don't think it's nitpicking at all, this is the most basic stuff you need to think about when doing dieting - CICO is naive at best.
                • gassiss 9 days ago
                  yeah, foods with more fiber will also make you less hungry, which in turn makes you eat less calories...

                  CICO is a great approach for the general population, and works great even amongst professionals that have weight management as their career (bodybuilders).

            • hooverd 10 days ago
              Basic physics says a human can live on a cup of gasoline a day.
              • scotty79 10 days ago
                Sure you can! You just need to figure a way to digest it. Ask chemistry.
          • jononomo 10 days ago
            I can't stand this "it's just physics" talking point when it comes to calories and weight loss. Why don't you try consuming exactly as many calories of gasoline as your body burns each day and then tell me whether you lose or gain any weight?
            • asdff 10 days ago
              I think the assumption with trying to be healthy and track your calories is you are eating a healthy and balanced diet, and not things like potato chips, candy, or gasoline all day. Then with healthier food choices a consistent value for you in your life, you don't have to worry about that Starbucks drink that's 600 calories because you just wouldn't be drinking those things with this new mindset. Then it doesn't even matter your metabolic rate either; if your diet is consistently healthy and you are measuring calories and your weight on the scale, then you can dial back caloric intake and see results on that scale.
              • jononomo 10 days ago
                All I know is that if I gorge myself on only eggs and fatty ribeye steaks for weeks on end, then I’ll lose fat, gain muscle, and look good naked. Burn if I eat carbs and drink beer then I gain belly fat and look terrible naked. I never count calories.
                • asdff 9 days ago
                  Drinks, not just booze, are sleepers for caloric intake. A can of coke or a small bottle of gatorade are 130 calories. Then you have some people who literally hate the taste of water for some reason, so every drink they take of a liquid comes with calories. Just switching to water alone for a person like that could cut out hundreds of calories right there with no other changes to diet or lifestyle.
            • scotty79 10 days ago
              Basic physics 100% tells you you won't gain weight in that case.
              • jononomo 10 days ago
                Are you certain that humans can properly digest gasoline and make use of its calories?
                • scotty79 9 days ago
                  I'm sure that they can't. That's why they won't gain any weight with such diet.
                  • jononomo 9 days ago
                    So you're saying that the type of calories you consume makes a difference, not just the amount???
                    • scotty79 9 days ago
                      I'm just saying that whatever calories you consume you won't have more net gain of weight than contained calories you consume minus calories you burn.

                      Regardless of whether calories are completely indigestible or totally digestible the above still holds.

                      Also you don't have to resort to gasoline. If you want to loose weight you may use cellulose. And if you don't eat more calories in it than you need to keep your weight then you won't gain weight regardless of how much cellulaze (cellulose digesting enzyme) you eat with your cellulose.

          • subharmonicon 10 days ago
            It’s not that simple, although it may seem that way for some people.

            Twice I have been on very extreme calorie counting regimens for months at a time combined with substantial weight lifting and cardio.

            Both times I have observed that if I reduce calories the first thing that happens is I start to feel colder in the same environments. My body adjusts to my new caloric intake by reducing my metabolic rate it seems.

            I learned about the idea of a “set point” fifteen years ago and I believe it’s related to what I’ve observed.

            I have friends who can do something as simple as cutting out a morning cappuccino and they lose weight as a result. If I do that, there is no measurable difference unless I cut much deeper and substantially increase activity at the same time. Then the weight comes off for a bit and then plateaus again, sometimes for weeks or until I make another adjustment.

            One of the times I went through this weight loss regimen I had an air displacement plethysmograph near the end of the weight loss that concluded I had 178lbs lean body mass. I had likely bulked up a little through all the weightlifting I was doing but have always had a fair bit of muscle so you might expect my resting calorie burn to be very stable and for small adjustments in calories to not impact resting metabolic rate, but that’s not what I observed in practice.

            • syzarian 10 days ago
              If metabolic rate changes due to caloric restriction then this doesn’t negate the view that basic physics dictates that calories in minus calories out determines weight loss. It just means that a corresponding change to calories out can occur with caloric restriction. It is a physical reality that calories in minus calories out determines weight loss. It is also a reality that adhering to this might be very difficult for reasons you suggested.
              • MacsHeadroom 10 days ago
                Nobody is contesting the physical reality of CICO; what they are contesting is that the "calories out" section of the diet is as easily controlled as previously thought.

                I'm supposedly on a 1500 calorie deficit, eating ~1300-1500 calories a day and burning ~3000, according to my fitbit. But I'm only losing about 0.5lbs per week.

                My conclusion is that I'm really only burning 2000 calories despite HIIT 3x/week, strength training 4x/week, and cardio 6x/week. If it weren't for all this training I would likely be gaining weight on what would otherwise be a reduced calorie diet for someone my size per every major TDEE calculation

                • Frost1x 10 days ago
                  >Nobody is contesting the physical reality of CICO; what they are contesting is that the "calories out" section of the diet is as easily controlled as previously thought.

                  I'm not so sure about that, I see a lot of claims otherwise on this article's thread which blows my mind a bit.

                  It's definitely an issue calculating and managing the calories out portion and for some people, it may not be an effective model to manage weight with diet and exercise, but I'm reading a lot of "this model is wrong" which is a little baffling to me.

                  Is it possible the caloric measurements are off? Absolutely, we may not even be considering all metabolic pathways, but hopefully a lot of its getting covered. CICO should be used as anchor points to help you guide your diet and find what works for you because everyone is a little different. Don't like a lot of vegetables, coffee make you sleepy and lazy? Hate cardio but love weight lifting or vice versa?

                  Try something else, but CICO can help you make a better grounded basis of comparison here to find what mixture works best for your body to manage weight and get or keep the body composition you desire. Does the model simply not work for your lifestyle? Try something else! But is it wrong? Eh, I don't think so.

                  • elenaferrantes 10 days ago
                    CICO while thermodynamically true, is not _that_ useful because no one really control CI nor CO …
                • yamtaddle 10 days ago
                  I did a strict 1400 calorie per day diet for a few months in college. Zero cheating. Also kicked up aerobic activity a ton.

                  Losses were at like 5-10% the rate they "should have" been. Totally worthless.

                  Meanwhile weight lifting has always worked for me a large multiple as well as it "should", for weight loss, if you go by calculators that try to figure how many calories an activity burns.

                  I reckon that in both cases those two approaches must be having large (and opposite) effects on my resting metabolic rate.

                  • asdff 10 days ago
                    Aerobic activity is not all the same either. Some people run for a mile and think that's good, they are maybe burning only 300 calories doing that though. They hike for 4 miles and its another couple hundred, or its blown with the granola bars. If you bike for an hour at less than 10mph you are burning like 300 calories, but if you bike for an hour at like 16-20mph then you are burning like 1000 calories.
                    • sasawpg 9 days ago
                      Unlikely you'll be burning 1000kCal at 16-20mph unless you're going up a steady incline and keeping that speed (i.e. high power). That is a bit of an exaggeration. The remainder of your point stands - cycling is a great way to burn a lot of calories.
                      • asdff 9 days ago
                        You'd have to be pushing 250-300 watts an hour to burn that much, but people do burn that much in an hours time if you look around a few bike forums. If you have time to do a long and leisurely ride, 3 hours or so, the length of the new Avatar movie, you'd probably knock out at least 1000 calories imo. Whats nice about a road bike in particular for caloric burning, at least in my experience, is that it makes you want to push the bike and go as fast as you can and keep snapping up through your gears and catch up to the cars (passing them even when they hit traffic or you are descending).
                        • sasawpg 9 days ago
                          At 25% efficiency (on the high side), 1000kCal is about 1050kJ, which is just shy of 300W. Most adults can't sustain 300W for an hour. In addition, reasonable riding conditions (flat, low to moderate winds) will get you moving faster than 20mph at 300W. Most adults are definitely not burning 1000kcal riding a bike for an hour and even fewer are doing that rate of calorie burn for longer than an hour. I regularly have >1000kcal rides, but I have yet to hit 1000kcal for a single hour at my highest intensity. I can do close to 300W for 20 minutes after which time the power drops off rapidly. Larger cyclists that are trained can absolutely sustain 300W for an hour, but won't do this without a significant training effort.

                          I don't mean to imply that you won't burn a lot of calories cycling, quite the opposite, I think it is one of the easiest and gentlest ways to do so. You are however overstating what most non-elite cyclists can regularly accomplish in terms of calorie burn per hour.

                          Source: I have averaged 450hrs/yr for last 3 years and closely monitor my data.

                • kasey_junk 10 days ago
                  Both your calories in numbers and calories out are subject to extreme estimation error.

                  Also body composition changes can make “weight loss” difficult as you replace fat with muscle. You can also get a gross estimate of muscle/water/fat mass to see those changes (or go get a very accurate measurement a few times in a facility equipped for such things).

                  • caeril 10 days ago
                    This is generally the correct answer.

                    Online TDEE calculators almost always overestimate expenditure, as do smartwatches. On the intake side, people lie to themselves constantly. First, they generally don't actually weigh their portions. In the rare event they really are weighing their food, they'll "accidentally" load up 4.3oz of something, then input it into their tracker as 4oz. Then they'll neglect to log their sauces and condiments, because it's "only" 20kcal for a tablespoon. These discrepancies add up.

                    Invariably, these ridiculous claims come down to people being liars, not just to others, but to themselves.

              • hooverd 10 days ago
                What people do believe is that you can neatly tabulate calories in and calories out.
                • asdff 10 days ago
                  Tabulating calories in and weight out is a lot easier, especially if you eat healthy and simple foods.
              • aantix 10 days ago
                If you want to increase muscle mass, why don’t you just keep lifting increasingly heavier weights?

                If you want to lose weight, just keep eating increasingly less calories.

                Because that trivializes the problem. There’s physiological pushback on many dimensions.

                • syzarian 10 days ago
                  I suggest a better response to CICO is not that this isn’t true but that it is hard for a variety of reasons. One’s response to CICO ought not be to deny basic physics. There was a comment that it is basic physics that CICO is true and it got pushback. My post was to point out that the pushback against that comment were wrong in the sense of not actually disputing CICO.

                  The responses should have been of the form, “Absolutely but this is very hard for some people for the following reasons…”. That changes to one part of the equation can have unintended consequences that change the other part.

                  • cico3646373 10 days ago
                    It's not so much that I would dispute the physics, but I personally wonder about digestion. This strict cico model seems to make the assumption that every digestive system extracts the same amount of energy from the same foods, which I find unlikely but am certainly not an expert. If I eat a bunch of grass, I am pretty sure I'll probably get sick and have some unpleasant bowel movements but I won't draw many calories from the grass. Unlike a cow.

                    Personally though, I find it rather easy to maintain a particular weight. I just wear pants with the right waist size and if they feel tight I take it easy on eating for a day or two. I have had the same weight +/- 1.5kg for 20 years. Losing weight beyond my comfortable baseline is exceedingly difficult though.

                    • asdff 10 days ago
                      That's not really how I interpret it at least. I think its assumed there is no one with a perfectly efficient digestive system, and that there is variance in efficiency based on a plethora of factors. However, that efficiency rate hardly matters. You are in effect a car. Some people are hybrids, super efficient perhaps, while others are SUVs guzzling gas to go the same distance. That being said one thing is true for all of these cars: if you put in 9 gallons instead of 10 gallons into the tank, you will go for less miles than if you put in 10 gallons. In other words, if you are being accurate about measuring your calories in (the gas) and you are measuring your weight (miles driven), you can adjust the input calories to effect your output weight. Exercise then is like driving in low gear with the engine at a high RPM; you are burning more calories in a given amount of time just like you'd be burning more gas in a given distance running at a higher RPM.
                  • kritiko 10 days ago
                    Here’s a quote from Kevin Hall, who does metabolic studies at Harvard:

                    >The problem is that CICO as the law of energy conservation is NOT a model of obesity. It's conflated with the straw-man "Conventional Model" described by Ludwig: independent, unregulated intake and expenditure implying that getting fat and treating obesity are all about willpower

        • airbreather 10 days ago


          The CSIRO has been researching for decades as to what the best bang for buck is with regards exercise.

          • dmix 10 days ago
            There's no doubt exercise is essential here. There's just lots of people pushing the idea that diet / food restriction alone is sufficient for weight loss or that the goal of exercise is to "burn calories", suggesting the two are directly correlated.
            • jasode 10 days ago
              >There's no doubt exercise is essential here.

              In the isolated context of losing weight, it doesn't seem like exercise is essential. Or to state in less absolute terms, exercise has less influence than diet choices for purposes of losing weight and maintaining it.

              In my case, I noticed that the pounds melted off when I stopped drinking sugary sodas and eating bread/snacks and switched to more vegetables with olive oil. In contrast , when I started exercising regularly, I actually gained more weight.

              The thing that messes up the simplistic idea of "exercise burns calories so with 2nd law of thermodynamics you lose weight" ... is the body's overwhelming desire to maintain homeostasis. (https://www.google.com/search?q=homeostasis)

              Homeostasis means that more exercise can cause more hunger and thus bigger meals which offsets the exercise so no weight is lost.

              Likewise, deliberately eating less can cause the body to conserve energy and do less physical activity which re-balances the body to not lose any weight.

              For many folks, a long-term way to adjust the homeostasis is to change the diet from high-carb to low-carb and switch out the 400-calorie Starbucks frappuccinos and sugary sodas to green tea and 0-calorie sparkling water. These diet alterations have more chances of success than maintaining the discipline of burning 500+ calories a week via exercise.

              Exercise is essential for healthy heart and bone strength but there are counteracting factors when used as a tool to specifically lose weight.

            • roflc0ptic 10 days ago
              I don't understand what you're saying:

              > people pushing the idea that diet / food restriction alone is sufficient for weight loss

              Diet/food restriction alone is strictly sufficient for weight loss: I'm pretty sure this is uncontroversially true, but it sounds like you're saying it isn't. Am I misunderstanding you?

        • SalmoShalazar 10 days ago
          Absolutely ridiculous to call this a “meme”. It is the most basic fact about how to lose weight. Stop eating altogether and see what happens (spoilers: you’ll lose weight as your body devours itself because your body needs calories to operate)
          • watwut 10 days ago
            > Stop eating altogether and see what happens (spoilers: you’ll lose weight as your body devours itself because your body needs calories to operate)

            You might just die before you loose all that weight. Moreover, you have high chance to develop long term health issues.

            • scotty79 10 days ago
              You might die all the time for any reason.

              If the issue is lack of some specific vitamins or minerals you may correct it before you die without starting to eat again.

        • jokethrowaway 10 days ago
          Calories are a good enough metric. There are exceptions: It's hard to calculate how much energy your body will spend to digest food burning energy in the process. Eg. nuts are high calories but also increase the amount of energy you're burning.

          If you worry about macros (eg. hitting your proteins) you can get even better results by building muscle (which increases your metabolism and make you burn more fat) and avoiding a bunch of health issues likely linked to eating modern processed crap.

          That said, the phrase: > without making your calorie intake less than your expenditure you will not loose weight

          is correct and not a meme. It's just that your expenditure is hard to track and can be influenced by a lot of factors.

          What I found that works wonders is to: - 1. keep your diet and fitness regimen as constant as possible, no matter what it is - 2. swap food with lower calories and higher protein intake, while trying to avoid processed food - 3. increase exercise without adding food - 4. measure your weight every morning at the same time - 5. do that until you stop gaining weight and your weight is constant for a few weeks - 6. reduce calories by doing step 2 or 3 again until you start losing a bit of weight - 7. keep doing it until you hit your target weight

          I did this to lose weight years ago and it worked well. The main advantage is you don't have to worry about counting calories.

          Last year instead I just went carnivore (admittedly, I did it to sort out other health issues, the weight loss was a welcome side benefit) and I found myself feeling full (thanks to the higher fat intake) and eating a sensible amount of meat, which helped me lose 10kgs over ~10 weeks. I'm sure not eating carbs (ketosis) also played a role.

        • edanm 10 days ago
          > I've asked on HN a couple times in the past for citations that support this meme and haven't yet found a good source on this.

          This is not a "meme", it is almost universally accepted science by nutrition scientists at this point. This includes both theoretical reasons, as well as actual, legit studies with human subjects.

          > Calories seems to be the catchall metric pushed around, but it seems to be as much about what you eat, not just eating less.

          Not sure what you mean by "it" when you say "it seems to be as much about what you eat."

          > Whether calories is the thing that matters is the question.

          Matters for what?

          If you mean in the strict sense that you are able to control someone's total food intake, then yes, you can induce any amount of weight loss you want by limiting their caloric intake.

          If you mean "matters" in terms of getting real people in the real world to actually lose weight? That's a much more complicated question, because the number one variable that controls the amount and duration of weight loss is how long you stick with the diet.

          Any "diet" that causes a caloric deficit will cause weight loss. Some do this by directly counting calories and targeting a lower number. Some do this by causing you to eat foods that make you fuller, thereby making you limit the amount of calories without thinking about it. You can even take medication that just cause you to not be hungry, which is the most effective in some sense.

          The thing is, most diets are hard to stick to, or at least most people don't stick to diets. I personally counted calories as I found it the "easiest" in some sense (though I also had to learn a lot about how to eat in a more satiating way so not to be hungry.) I used that to lose a lot of weight. I've now regained a lot of that weight, partly planned (as part of a bulk), partly unplanned (I got injured so stopped training, and then decided to focus less on weight control and eat more, knowing that I would gain weight in an unplanned fashion.)

        • tallytarik 10 days ago
          You go so far as to refer to the parent’s comment as a “meme” and then seem to agree with it by saying “I'm sure that would still ultimately contribute to weight loss”

          You are also correct - caloric deficit is not very sustainable long term for a large number of people.

          There is ongoing study to figure out why — for example, why some people are much less able to stick to a diet, or have constant food cravings, and so on. That’s not at odds with what you’re questioning. The focus is on those areas because the requirement of a caloric deficit for weight loss is one of the most reliable observations we have so far.

          • asdff 10 days ago
            I think there is a huge mental aspect with feelings of hunger that needs to be learned how to be dealt with. I used to work a pretty labor intensive job, and you would get hungry in the shift and would just have to tough it out with your stomach raging all day. After all of that experience, I can fast at will without it putting me out really (helpful during long days of airport traveling where the food is overpriced anyhow).

            That's nothing compared to what some people had to deal with e.g. surviving famines. That takes some serious mental fortitude, but I would imagine after that experience you'd be perfectly fine if dinner was served late. If you ever read Siddartha, there's this part where the protagonist learned how to fast with the Samanas in the forest, and not everyone knows how to deal with that sensation and accept it as just another sensation in life.

            On the other hand, I know people who get into this bizarre state if they are hungry, not long after whatever their normal mealtime might be sometimes. People joke around about being "hangry" but its a real thing for some people. I can see how if you haven't learned how to accept the sensation of hunger, and all you know with that feeling of hunger through your life is to immediately satiate that sensation, sticking to a caloric deficit would not be easy.

        • tvrg 10 days ago
          I have the same question: People often calculate with calories as if it is really simple math. But - honest question - does my body really have to suck up every calorie or could it excrete some calories in the toilet and also vary that amount depending on my caloric intake? For example, I have read somewhere that you urinate superfluous proteins - which also have calories. Also, if I'm hungry I get cold. I might put on another layer. So my "base energy expenditure" could vary with the amount of calories I eat, right?
          • clnq 10 days ago
            We don't suck up all calories from what we eat. We know this because our fecal matter burns. What you have on dietary labels are dietary calories, which is what a typical human body can absorb. Not the "fuel" calories.

            I think the understanding about dietary calories comes from the agricultural world where calories are much more involved in the economics of animal growth and weight gain. So we might not even be that sure that what we consider dietary calories are accurate for humans.

            Assuming they are accurate, each individual digests a different % of all calories they ingest and it depends on many factors. It's a very imprecise science.

            If you want, you can eat a given number of calories each day of just one meal (like Huel or Soylent) for a month. Then, for the last week of the month, you can see how much weight you gained or lost over 7 days. You will also need a medic to estimate your basal metabolic rate and you would need to stick to your daily physical activity habits consistently. And then you can arrive at some number of what % of dietary calories you absorbed for that particular food with those particular eating times, exercise habits, and so on.

            I think it's a very impractical test. Maybe it might be easier to do in a very controlled environment in terms of energy expenditure, like in weightlessness. But then the weightlessness is a factor in digestion, too.

            If someone found a way to accurately determine what % of dietary or fuel calories humans really absorb, the data would probably be as impactful in our understanding of diets as the Minnesota starvation experiment.

          • Frost1x 10 days ago
            Your body isn't 100% efficient, some energy will be lost so assuming you have a perfect measurement of intake and expenditure, you're not completely sure how much of the intake your body has consumed. There are some estimates of these things. One thing you can do though is if you understand how your body metabolizes certain foods, you can measure the upper bound of energy consumed. With accurate measurement you can say that your body couldn't possibly have gained more energy from this given food than this amount. You can then use that upper bound figure to try and guide your expenditure. If you make sure your expenditure meets that upper bound and still creates a deficit, you know the deficit is at least that amount, likely more since 100% energy conversion isn't feasible.

            External factors certainly come into play like environment. You're not a completely closed system as you point out based solely on food. You may sit in a cold office shivering throughout the day or in a hot room sweating, these factors will effect your energy expenditure (and even intake) differently just to maintain your existence.

          • User23 10 days ago
            Metabolic ward studies have proven that the body will excrete excess protein via the kidneys. Theoretically a glycogenesis to lipogenesis pathway might conceivably exist, but under controlled conditions it observably doesn’t.

            Something similar will happen with excess ethanol consumption. Your body will preferentially use ethanol for immediate energy needs, but there is no pathway to store it as fat. However any fat or carbohydrates in the diet will immediately undergo lipogenesis while the ethanol is metabolized.

            The end result is that it’s physiologically impossible to gain body fat on a diet of lean protein and wine or spirits. However that’s a rather unhealthy diet otherwise so I wouldn’t recommend going all in on the piss out the protein plan.

            It’s good to know though that if you’re taking an alcohol cheat day then stay away from beer and mixed drinks as well as fat and carbs all day and until the next morning. Instead eat something like lean chicken or fish with near zero calorie vegetables like lettuce or cucumbers or what have you.

          • asdff 10 days ago
            The idea is that you have a healthy lifestyle along with caloric tracking. So you are working out regularly each week. You'd be eating a consistently healthy diet versus e.g. a sugary drink worth a few hundred calories that isn't making you less hungry.

            Then your actual rate, whatever it is or how much it varies, hardly matters long term. Sure there would be variance, but on the whole, long term, you are only caring about the weight on the scale. So you measure calories in and your weight, and given you are consistent about burning calories exercising and the food choices in your diet, dialing back calories in will make a change on the scale, maybe a bigger or smaller one for different people, but a change no less. No one runs on air.

          • bluGill 10 days ago
            Not only excrement, you also have to factor in sweat - your body can "choose" how much to burn into heat, and then use sweat to keep your body temperature normal if it is creating more heat than needed. This is normal, but I'm not sure if there is anything you can do to control it.
          • goodpoint 10 days ago
            Correct! CICO is often oversimplified by ignoring that our digestion is far from 100% efficient and our base metabolic rate can change.
        • shlant 10 days ago
          > I've asked on HN a couple times in the past for citations that support this meme and haven't yet found a good source on this

          I have a hard time believing this. Here is the first link from googling "cico weight loss studies":


          it's only a "meme" to those that have been convinced by people who are trying to sell you a specific diet/lifestyle (most commonly fasting or low carb)

        • Frost1x 10 days ago

          Food (calories in) is just a form of energy your body is capable of utilizing. Fat is just a physical medium to store energy for use in your body. For your body to move and perform actions (live), you require energy. All things considered at this scale, if you expend more energy than you consume, you'll ultimately either die (due to lack of energy) or use other forms of energy in your body (e.g. fat).

          This is of course the 30,000 ft view and there's a lot of complex biology and chemistry going on but it's pretty straightforward if you believe the law of conservation of energy is correct and our bodies aren't doing some sort of nuclear physics to process energy and instead relying on various forms of chemical and physical energy.

          As you point out, it's not so cut and dry though in practice. There's a time component here and our bodies get quite clever. We build up efficiency of certain tasks over time requiring less energy usage. We resist building muscle because it requires more energy to maintain. Some food's energy density isn't perceived very well by our bodies and we remain more or less hungry irrelevant of potential calories making it more difficult to maintain a calorie deficit/diet based solely on our bodies senses. Many nutritional information products don't accurately measure calories of food, sometimes making it difficult to use as a base metric (theres a lot of errors in these measurements, especially by small food producers/providers). We also have incredible difficulty trying to estimate how many calories our body is actually expending because it's a fairly complex system (the "calories out" part of the equation) although there are some figures out there to help you estimate these within some general ranges depending on factors like age, diet, fitness, activity and so on--it's not perfect but it's something to work with quantitatively.

          The benefit of calorie counting though is that there are fairly basic physical and chemical principles at play that make it a useful tool in weight loss and management. Even if a bit variable (both the in and out) and sometimes inaccurately represented, it gives us something fairly quantitative to work with, measure, and change around to control our weight. We can measure it and change other variables in our lifestyles to, over time, manage weight. It works and the statement is valid but it's not simple to use by any means, there's a lot one needs to learn over time to better learn how to measure their in/out and overall body feeling based on these factors.

          • watwut 10 days ago
            Linking conservation of energy is just non argument. It has nothing to do with anything, because our bodies are not simple theoretical machine.
            • this_user 10 days ago
              They are still subject to the basic laws of physics. If you do a certain amount of work, but you take in less than what you have spent, the body has to use its stored energy to make up for the difference. How else would this work? The body cannot magically materialise energy out of nothing, and it cannot use more than what is available in the form of intake plus storage.
              • watwut 10 days ago
                > They are still subject to the basic laws of physics. If you do a certain amount of work, but you take in less than what you have spent, the body has to use its stored energy to make up for the difference. How else would this work? The body cannot magically materialise energy out of nothing, and it cannot use more than what is available in the form of intake plus storage.

                Your body temperature goes up and down, changing how much energy is spent by body. Your ability to perform goes up and down - you become sleepy and tired, your brain spends less energy and that is that (yes it has impact on your attention and performance). You cant stop it from happening. You may try to exercise the same and can easily become unable to.

                Your body gets rid of calories in poo and piss, when sweating or not.

                Your body can just turn off functions and generally malfunctions and you dont have direct control over it.

              • kelseyfrog 10 days ago
                Basic laws of physics is a misnomer. If I consume gasoline which has calories in the physics sense (31,000kcal/gal), it doesn't affect my weight. CICO is a broken model because it doesn't account for this.
                • Frost1x 10 days ago
                  Calories on nutrition labels should account for potential metabolic energy, not total energy, so the example of gasoline isn't by any means a disproof of the model at all since gasoline is obviously not a food source you safely metabolize.

                  If we looked at total energy of your gasoline we'd need to consider mass to energy conversion as well... but your body can't do that either. Energy your body can metabolize is clearly a subset of total energy available. It's certainly an estimate and it's not perfect but it's useful.

                  • kelseyfrog 10 days ago
                    Right, and what factors modulate the actual metabolic energy?
                    • Frost1x 9 days ago
                      Well that's where all the biochemistry comes into play. There are pathways where various components are broken down through physical force, stomach acid, gut bacteria and enzymes, etc.

                      This looks like a digestible introductory guide: https://themedicalbiochemistrypage.org/digestion-and-digesti...

                      And a brief description of how all that helps inform calorie counts on nutrition labels: https://en.m.wikipedia.org/wiki/Atwater_system

                      People make entire career studying these sort of processes. Over time the information is refined. All of this ultimately helps inform how we measure and quantify things like calorie counts on food labels. Again, not perfect, but the process works and improves over time. It's a complex macroscopic system relative to the underlying chemistry and physics but if we assume larger systems are built on, composed, and governed by principles of constituent systems then we have a way of slowly understanding these complex processes and using that knowledge to our advantage.

                      Just as with software systems we rely on abstract processes below us to talk about things. That doesn't mean the high level abstractions are ignoring the details, it's just that there's value in talking about things simplistically like "calories in" and "calories out" without people looking to take very literal interpretations and trying to convert total energy possible into kcals. Heck, this is why they're "Calories" and not "calories" and why "Cal" has even been proposed to help avoid this sort of confusion.

                      • kelseyfrog 9 days ago
                        Right, this is a very long way of saying that CI = modulating factors * CO which is the point I've been trying to make.
            • foobarian 10 days ago
              I suppose you have evidence of bodies producing more energy than input? Do tell...
              • watwut 10 days ago
                We piss and shit out calories. Our temperature goes up and down. Bacterias in our guts eat calories, making us absorb more or less. There are multiple health issues that will make you loose or gain weight quickly with zero change in lifestyle or food. Oh, and we become tired, weak and passive which makes us spend less energy then if we are feel good.

                The assumption that body resembles simple closed physical model is absurd.

                • foobarian 10 days ago
                  OK then let's lock a bunch of us in a vacuum thermos like in that "DEVS" show, have them eat a reasonable diet of 2k calories a day, have them walk on hamster wheels and hope they will produce > 2k calories worth of energy. Scale out, profit! Spoiler alert, this will not work.
        • yamtaddle 10 days ago
          > I've asked on HN a couple times in the past for citations that support this meme and haven't yet found a good source on this.

          I think I finally figured out why I hate CICO so much: it's usually presented in a motte-and-bailey style. It's used to dismiss more-complex advice or observations and presented as if it's all you need to look at to model weight loss and gain to a useful level, then when it's pointed out that the terms are so vague, hard to actually measure, and don't address the effects of feedback loops on metabolism, that it's like trying to model the behavior of aircraft with gravity but without lift, and therefore damn near useless, the fallback is "well it's still technically true, blah blah blah". Sure, it's technically true, it's just... not very useful on its own, and constantly bringing it up as if it's all that matters is grating.

        • frognumber 10 days ago
          If I cut my calorie intake by a moderate amount, I don't lose any fat. If I cut my calorie intake by an extreme amount, I start to lose fat.

          My hypothesis is that the equation that weight loss is related to calorie intake minus expenditure, but I think the conclusions one draws from it fail to take into account how much the body can control expenditure.

          My body seems to naturally drift up in fat weight, very slowly -- probably around a pound per year -- no matter how much I eat. If I cut calories a lot, I can lose fat. After that, my fat level drifts back up to the old target weight pretty quickly, and then up slowly again. I'm pretty sure if I plotted my fat from the time I became an adult, it would be a pretty straight line, with short-term dips and recoveries for diets.

          Losing weight sustainably would mean resetting that target somehow. I don't know how. Changing my diet and exercise levels don't seem to do much for fat levels (but do more for my general fitness and health).

          • sergiosgc 10 days ago
            That was my exact personal diagnostic, until 2018. My weight very slowly drifted upward, but you start adding 0.5kg-1kg per year over a couple of decades, with a few dips here and there on dietary effort, and the result was a health disaster.

            My solution, and mine alone after trying oh so many different diets and strategies, went through regular aerobic exercise, at a rate of 3-4 hours per week. In my case it was swimming, because I like it; cycling or running would have had the same effect, I believe.

            It worked. I lost almost 30kg over about 2.5 years. Why did it work? I don't really know. I can tell you that basal expenditure certainly has gone up, as I had to get into shape to swim 4-5km a week. Of course, swimming a few km introduces some expenditure of its own. However, I had already tried gym and other sports, which should have the same effects, with far worse weight control outcomes.

            So, for me, regular aerobic sessions of longer than 45min did the trick. I don't know why, so I can't promise it will work for anyone else, but you might as well try it for a few months. Don't expect huge, rapid, losses in weight, just a very consistent downward trend.

            • frognumber 10 days ago
              I had periods in my life when I was very seriously athletic. 8 hours per week of serious martial arts, and maybe 6 hours of cycling.

              I *still* had to really starve myself to lose fat. My aerobic fitness was excellent, as was my flexibility. My core strength was awesome. Fat was another matter.

              I'm not the only one like that.

              I know people for whom cutting down eating works, and people for whom exercise works. I'm not one of them.

              As a footnote, I couldn't lose 30kg without seriously injuring myself. I'm overweight, but not deeply obese. Losing 15-20kg would put me at an ideal fat level.

            • apelapan 10 days ago
              I can't say I seriously tried anything else, but the same approach worked magic for me. I started running and swimming, slowly ramping up to four hours per week (previously zero active exercise for the past 20 years) and have been consistently losing weight for 20 months now. About 15kg down from the starting point and no signs of stopping (though rate is slowly decreasing).

              At current trajectory I'll be at normal weight by summer. Two years ago and for many years before I was balancing on the edge between overweight and obese.

          • snovv_crash 10 days ago
            You probably subconsciously downregulate your physical activity when you reduce calories, due to lower energy levels. If you wear a fitness tracker and equate number of steps to high calories you should see a difference even with slight reductions in caloric intake. Even the amount of fidgeting you do during the day can change your base caloric expenditure.
            • wordpad25 10 days ago
              another thing is to measure total calories intake and spending weekly.

              Daily metrics can vary wildly without affecting overall result.

              • asdff 10 days ago
                Is spend even relevant to measure versus weight on the scale? Assuming you work out consistently?
          • robdar 10 days ago
            > but I think the conclusions one draws from it fail to take into account how much the body can control expenditure.

            Yes, this is has been observed and studied. From this page: https://physiqonomics.com/constrained-energy-model/ the relavent source materials are:

            https://pubmed.ncbi.nlm.nih.gov/26832439/ https://pubmed.ncbi.nlm.nih.gov/34453886/ https://pubmed.ncbi.nlm.nih.gov/34519717/

            So, yes, it seems that the body "compensates" and controls expendeture as you've suggested.

            Speaking in general, there are a lot of details to consider for CICO. When people count calories to below their TDEE, their estimate of TDEE is just that, an estimate, not their actual TDEE.

            When calories are counted, how accurate are calories being counted? FDA regulations in the US call for the nutritional information on packaging to be +/- 20%, and when audited, the information is often found to be outside that ranges.

            Every gram of glycogen stored in your muscles, the body also stores 4 grams of water. The cycle of exercise, fasting, caloric restriction, and refeeding and glycogen storage are going to cause large swings in weight that can make it hard to pull out trends until several weeks/months have gone by, but frequently people are micro-focused on daily weight flucuations and draw their conclusions about diet and weightloss from what is effectively changes in glycogen storage/water weight.

          • jononomo 10 days ago
            Conversely, you could increase your caloric intake and still lose fat if you ate only beef, which is the diet I recommend.
            • asdff 10 days ago
              Rabbit would be even faster but you do have to supplement fats to avoid dying.
              • jononomo 10 days ago
                You have to eat the fattiest cuts of ribeye steak to really make the "lion diet" work. (Yes, I know that Michaela Peterson named this diet and she and her father are morons, but the diet definitely works in spite of them.)
        • bliteben 10 days ago
          Calories are a unit of energy. You are arguing against chemistry and physics. Im sure you could find inaccuracies in calorie counts for various foods. Additionally Im sure some foods are more filling and/or healthy at different calorie counts.

          Arguing that calories in doesn't matter is nearly on the level of Holocaust denialism, as the main picture evidence there is of the effects of calorie deficits.

          • mister_mister 10 days ago
            They are unit of energy and that is correct. But they are not the unit of energy that cells use, they use ATP that is created from ketones, fatty-acids, glucose and oxygen[0]

            Measuring food through calories, which are derived from burning food is therefor quite old technology, it's from 1800 when steam engines where main way of powering the western world.

            As a thought example to push CICO model to it's end: For example we can't eat coal, but it's very calorie dense. According to CICO model we should be able to eat just little bit of coal, and drink tiny amount of fuel. So that would also suggest there is more to the story of nutrition then CICO.

            Mammals are not as simple as factory machines.

            For example CICO would suggest to lose weight to eat 500 calories less then normal, as average that would be 2500 for men. But if we would rephrase that: In order to lose weight eat 1/5 less then normal. Then that would have the same effect, that is issue with calories they tell a story about food but it's not the full story. [0]https://en.wikipedia.org/wiki/Citric_acid_cycle

        • criley2 10 days ago
          You are very right to question this!

          While the thermodynamics aren't assailable, it turns out that the calorie system is in fact quite fallable and bad!

          There's a lot of good material on why, I like this talk: https://www.youtube.com/watch?v=aJQxadvsmEQ

          But simply put:

          - Our system for measuring how much "calorie" is in any given food is extremely problematic and unrelated to how the body captures energy

          - Our system for estimating how much "calorie" a human body uses is extremely problematic and error-ridden.

          - Our systemized ignorance towards the relationship in the body between energy storage and energy consumption, as well as all the factors influencing this system. The same advice or strategy simply doesn't work the same way for two people. But our advice and labels can't capture that.

          As we engineers know "garbage in, garbage out". Well, when all of the data in this system is garbage, it's no surprise that the function outputs garbage.

          • foobarian 10 days ago
            The thing about the calorie system is that it's extremely simple and consistent. You could get into more advanced ways to count the calories that look at the type of food, and how body captures it, etc etc but that would be an even bigger mess than modern "dietary science."

            Currently the calorie count at least gives me an upper bound, and at least it's on the box and applies no matter who looks at it. How would you do better?

            • criley2 10 days ago
              Garbage in, garbage out. I believe "eating less food" causes you to lose weight. If you provide calorie numbers that correlate, I would ask you to demonstrate causation vs correlation, and I don't think you could do that as cleanly as you think across a broad population.

              A better system? Not quite sure, but as always: criticism of current failures does not, by rule, have to come paired with suggestions for improvement.

          • syzarian 10 days ago
            This does not dispute the fact that if the energy input into the system exceeds the energy expended then weight gain occurs and if the energy into the system is less than the energy expended then weight loss occurs. It may be hard to balance things in a healthy way and to achieve a desired result but the underlying physics is not a meme and not incorrect.
          • shlant 10 days ago
            "calories don't count" is a strong claim from a video that didn't provide a shred of evidence to support it
          • onionisafruit 10 days ago
            Thank you for the recommendation. I watched it and it answered some questions I had.
      • paulcole 10 days ago
        > training achieves the same effects as much longer endurance training at much shorter times

        For a very specific set of effects.

        Other effects vary widely person to person.

      • henrydark 10 days ago
        Unrelated, what if acronyms only contained adjectives and adverbs, and not nouns and verbs? I think we always eventually converge from something like "HIT" to "HIT training". Question for linguists
    • itsoktocry 10 days ago
      >In conclusion, if you're out of shape, you can improve a limited number of fitness measures just as much doing 3x8 minutes of higher intensity exercise as much 3×45m less intense exercise over 12 weeks

      This seems like a pretty negative reading. How about:

      Sedentary people (who have the most issues and highest healthcare costs), can see significant improvements in health by exercising for a fraction of time normally recommended.

      Sounds like wins all around.

      • notafraudster 10 days ago
        It's a win _if_ the barrier to getting sedentary people to improve their health through fitness is time cost and not all of the other costs associated with habit formation. My guess is for most sedentary people the biggest thing is that they manage to talk themselves out of doing anything, or once they start, talk themselves into allowing cheating/skipping rather than drilling in the habit.

        (Not that this is bad news regardless, it's good to have tools in the toolbox and some people might prefer lower time higher intensity stuff, but I do think the result is pretty limited)

        • Arch-TK 10 days ago
          Time cost is one of the major obstacles for more than just the reason of "it takes this X minutes out of your week". If you tell me I have to spend 45 minutes doing exercise 3 times a week my mind will be filled with excuses and the dread of how exhausted I will feel after 45 minutes and how it will likely be more like a 2 hour time commitment every time I do it. It's a much easier sell to say: 10 minutes where you're only spending 1 minute of time doing something intense and the rest is spent doing something quite light.
          • nottorp 10 days ago
            45 min is a streaming series episode. I've found that the only way to get my ass on a stationary bike is to stick it where I can see the TV and watch something brainless. Ideally fast paced and violent so I can pick up the rythm :)

            And admit it, no matter how busy you are you do watch some entertainment once in a while.

            • Arch-TK 10 days ago
              Of course I do but I watch stuff with my fiance, the idea of putting an exercise bike in the living room with her would likely not go down well.

              Likewise, in 10 minutes you can watch some short youtube video. The point is not that you can sweeten the deal of the 45 minute work-out to make it more bearable, the point is that when faced with 10 minutes of exercise vs 45 minutes of exercise, 10 minutes is a much easier pill to swallow _and_ is infinitely better than 0 minutes.

          • snapcaster 10 days ago
            I have yet to hear an _honest_ "i don't have time excuse". Everyone that has said this to me watches hours of netflix, dicks around on phone, etc. etc. Everyone has time, they just don't actually want to be healthy or in good shape. They want to want it
            • Arch-TK 10 days ago
              Nobody has time for anything they don't make time for, and making time for 2 hours of exercise related activities is far more difficult to muster (in terms of willpower) than making time for 10-20 minutes of the same.

              I'm glad that you have unlimited reserves of willpower and have no trouble with procrastination and as a result can just do any task on demand no matter how seemingly unpleasant it sounds, but unfortunately almost nobody on this planet is like that.

              This research is very positive and useful to get people who are currently doing 0 minutes of exercise a week to do 30 minutes of exercise a week, it flies in the face of a lot of "if you don't exercise for at least x minutes a week, you might as well not be exercising" bullshit.

              30 minutes of exercise per week (it doesn't really matter if it's high-intensity or not) is really much much better than 0.

              • snapcaster 9 days ago
                I'm not saying i'm perfect, just more honest with myself than using the "don't have time excuse"
        • watwut 10 days ago
          > It's a win _if_ the barrier to getting sedentary people to improve their health through fitness is time cost and not all of the other costs associated with habit formation. My guess is for most sedentary people the biggest thing is that they manage to talk themselves out of doing anything, or once they start, talk themselves into allowing cheating/skipping rather than drilling in the habit.

          I had exactly opposite experience. Time cost is rather major thing. Especially in the beginning, because it makes organizing your day much harder. Add an hour of anything and suddenly you dont have time to shop or cook or socialize or simply for your favorite hobby. Small time investment make it easier to transition and change lifestyle.

          And second, allowing myself to cheat and skipping does miracles for my ability to keep the activity long term. Whenever I set hard requirements on myself, following up became impossible in the long term. And since the attitude is all or nothing, it dropped to nothing.

          And third thing that does miracle for gaining long term habit is to prioritize pleasurable exercise, the one I actually like, rather then theoretically most effective one that sux.

        • strken 10 days ago
          I've gone through phases of being sedentary(ish), and I think it wasn't just time cost or cheating, it was going straight to high-intensity exercise because I thought exercise was "meant" to be difficult and unenjoyable.

          Most fit people have pretty good intuition about their bodies. They choose appropriate workouts, they don't run at high intensity too long and give themselves a stitch when they're meant to be doing endurance training, they know what it feels like to be lazy versus what it feels like to need a lower intensity rest day, they enjoy at least some of the exercise they do. When a sedentary person starts exercising on their own, they often don't know the benefits of training at a lower intensity, and adopt a "no pain no gain" approach, which is counterproductive if it doesn't build on a solid foundation of good habits.

        • SamoyedFurFluff 10 days ago
          Actually speaking as someone who is trying to become less sedentary the issue for me is a lack of knowledge, not a lack of time or whatever. I literally didn’t know what exercise was appropriate or even how to perform the ritual around exercise and everyone’s “just do something” was supremely unhelpful. I didn’t know what was normal soreness and what was an injury. I didn’t know what’s an appropriate warmup or cooldown. I didn’t know about eating and exercise, and would sometimes eat too close to exercise and throw up, or not fuel myself and feel extremely lightheaded/about to pass out. This made exercise much more challenging and intimidating, because there’s so much woo on the internet and you don’t have enough knowledge to sift through it. It’s like asking a layman to “do their own research” about idk flat earth or something.
          • watwut 10 days ago
            There are channels on youtube with prepared sets of workouts. I have seen people follow them with success. And also, I used app (freeletics, but there are plenty of others) to give me workouts which worked well for me.
            • SamoyedFurFluff 10 days ago
              Prepared sets don’t tel you about fueling yourself so you don’t feel too faint to continue, what’s soreness vs injury, etc. they also don’t confirm whether or not your form is good, so you can often injure yourself because super out of shape people very rarely have the body awareness/coordination to be able to self correct.
              • watwut 10 days ago
                I think that it is just overcomplicating it for the beginner. What happens when beginner cant continue or it hurts is that beginner will take a break until he/she can continue. I dont think beginner with no trainer to push him would overdo it till fainting.

                With a form, if you are going to claim that everyone must start with personal trainer to correct their crunches or squats form, pretty much no one will start exercising anymore. That is just going to be too expensive and time consuming. And among people I know who regularly exercise, none of them started with a trainer.

                • SamoyedFurFluff 9 days ago
                  I’m not claiming anyone should invest in a personal trainer. You’re putting words in my mouth. I’m just saying that things aren’t as easy or as simple as people describe due to a lack of basic body awareness and knowledge that comes with exercise. For example when I first started I developed severe back soreness the next day, to the point where I worried I had severely injured myself. Google was obviously unhelpful here, as “lower back sore exercise injury or not” is full of SEO spam. It was only when I got to speak with other friends who weightlifted more regularly that it was determined to be probably just soreness from not stretching.
        • matwood 10 days ago
          You're right. I get asked regularly about exercise plans from people who don't exercise at all. My response is always, 'don't over think it'. Just start doing something. All this focus on elite athletes lets people procrastinate by looking for their perfect plan.
      • epistemer 10 days ago
        Out of shape people don't stick to high intensity training.

        It takes awhile to get your lactic clearance up. Most people will quit after a few workouts because literally feeling like you are going to throw up is not fun.

        It is January so the gym is loaded with the New Years resolution crowd still. Most the people who started doing HIT on Jan 1st will quit by mid Feb. It is almost like clockwork and why I always reset and make January my recovery month.

        If anything HIT is probably a net negative because if you are out of shape it is just reinforcing the idea that the gym is a painful and miserable experience.

        • TheRealPomax 10 days ago
          Remember to make that bias explicit, also in part for yourself: "Out of shape people who join a gym don't stick to high intensity training".

          There is a huge difference between killing yourself over your lunch break/before dinner at home, and then taking a quick shower, and having to cut more than an hour out of your day because you need to drive to the gym, kill yourself for a very short period of time, then take several minutes to recover enough to feel you can safely drive home as a gross sweaty mess because you're far too uncomfortable showering around a bunch of strangers at the gym, and then do that multiple times a week. That's not just a commitment, that's a complete daily habit overhaul. Your life is now dominated by having to go to the gym.

          Folks who decide "yes, I think I can spend 15 minutes a day, three days a week, on this" at home, with some expert advise from reputable fitness coaches who run also youtube channels, without any of the time investment, inconvenience, and complete upending of daily routines that comes with attending a gym, might have a different success rate (and we'll never hear from them. If they keep it up, they just get in a bit better shape and move on with their lives).

      • petesergeant 10 days ago
        > can see significant improvements in health

        Where are you getting that from? Are the changes seen in the fitness factors especially significant, and if so, how significant? What's the expected health outcome here?

    • oxfordmale 10 days ago
      Exercise doesn't result in changes in body mass (weight loss), unless accompanied with a diet.


      • gadders 10 days ago
        Like the saying goes, you can't out-train a bad diet (unless you're a complete outlier like Eddie Hall or Micheal Phelps or DK Metcalf).

        This is a good podcast on the topic as well: https://www.artofmanliness.com/health-fitness/health/new-sci...

        • mister_mister 10 days ago
          Reading about the diet of DK Metcalf that is Low carb, Intermittent fasting, with plenty of vegetables is according to the latest science. Eddie Hall has goal based diets, Normal people wouldn't be able to process the amount of food he eats, can't be healthy to eat that much. But at the same time it's clearly working for him. Just saying genetics does a disservice to them.
          • SalmoShalazar 10 days ago
            Intermittent fasting contributes nothing to weight loss beyond the psychological effect, which may result in calorie restriction. This is the latest science.
          • type-r 10 days ago
            How can a diet both be plenty of vegetables but also low carb? As far as I know basically all vegetables are 50~70% carbs.
            • mister_mister 9 days ago
              Low carb diet is about lowering the amount of carbs someone consumes, only some vegetables that have many carbs or starches are best to avoided, because they have more then 60% of their content in the form of carbs vs less then 10% for other vegetables. on the list to avoid, or eat limited amounts are Potatoes, rice, grains.

              For example: Broccoli has 6 gram of carbs per 100 gram vs rice that has 80 grams of carbs per 100 gram.

          • gadders 10 days ago
            I think they are genetic outliers, but they are also outliers in the stresses they are putting on their body. They genuinely need ~12k calories per day (Hall and Phelps).
            • mister_mister 10 days ago
              They are genetic outliers because are able to operate at a elite level, but if you would learn more about sport and nutrition then those diets wouldn't look so extreme. They are eating goal based diets, that's different diet then normal person could or should consume. Hall and Phelps diet is not one that very sustainable but Metcalf one is actually the quite similiar to longevity diets. As such statements about that they are just genetic freaks this a disservice to diets they are eating and what we can learn from that.

              If they would 4k their bodies will start to adjust to those levels, would that be their top performance probably not. The human body is very adaptable to any kind of circumstance.

        • stockboss 10 days ago
          I don't think Eddie Hall is a good example of being able to "out-train a bad diet". He eats and trains for one very specific purpose - to get stronger. His physique reflects that. He's pretty fat, don't let his visible abs fool you.
          • gadders 10 days ago
            I've met him, when he was 3 times UK strongest man before winning WSM. He most definitely was not fit for daily life but was in good shape for strongman.

            By saying "out-train a bad diet" I mean he needs his reputed 12k calories to build and repair his muscle mass (obviously some went to fat as well). The people on "America's Fattest People" (or whatever) don't need 12k calories a day and get (the bad kind of) huge as a result.

      • CPLX 10 days ago
        This is nonsense. Try running 70 miles a week on the same diet and see if you weight the same after a few months.
        • etothepii 10 days ago
          I can't abide this line that it's all about diet. I'm a big guy >270lb. When I moved in 2017 I was living 4.5 miles away from my job down this beautiful disused old railway line. "Jogging" and eventually running the 9 miles a day to get to and from work caused me to lose 80 lbs. Stupidly once the weight was off I bought a car and stopped and over 3 years the weight came back. So much of this stuff is whether you were conditioned from childhood to be active. You can change that, but you probably won't do it on a treadmill in a gym a couple times a week.
      • kevin_thibedeau 10 days ago
        Yes it can. I had an injury that prevented me from cycling for over a year and slowly gained weight. It all came off after resuming a normal routine without dietary changes.
        • epolanski 10 days ago
          Well whether you lose/gain weight depends on (caloriesIn - caloriesOut) it's no rocket science.

          If you didn't compensate anymore as much for lowering the calories out you're obviously going to gain weight.

          • nolok 10 days ago
            So what you mean is your original comment could just have much said "exercice results in weight loss unless accompanied by a corresponding change in diet to increase calories intake", aka exercise alone as a change results in weight loss.
            • newaccount74 10 days ago
              People get hungry after exercise and automatically eat more to compensate for the spent calories.

              If you start exercising, but don't watch your nutrition, you will most likely not lose weight.

              • saiya-jin 10 days ago
                I don't get why folks often need to reduce such a complex and unique system as our body and its metabolism into some few word description.

                You are correct, and there is more, much more: psychology, how our body adapts to training, and so does metabolism. One random example of this vast topic - its well known in weightlifting community if you do hard compound exercises near your limits (squats, deadlifts etc) your metabolism switches to 'higher' burn rate (basal metabolic rate IIRC) and you can basically consume more. One sure way to lose weight if thats the goal, but one should never start weightlifting with those exercises, at that intensity.

                Also, again generally, its pretty non-smart to take sedentary individuals and expose them to HIIT as the study did, even if its just spinning. Body should gradually adapt to workload (=stress) and HIIT should be the final step in training, since its so taxing. Otherwise injuries and lose of motivation will happen more often than not. The systems that need adaptation are numerous - muscles, tendons, ligaments, cardiovascular system, nervous system etc.

                People are just looking for quick solutions to problems that don't have ones, not good long term at least. Same as diet fads. The cold hard truth that permanent change of fitness/BMI/overall health for the better requires permanent change in nutrition, training and TBH at least a bit overall life approach. Why not start with that?

              • cj 10 days ago
                >People get hungry after exercise and automatically eat more to compensate for the spent calories.

                This isn't universally true.

                Exercise significantly decreases my appetite for about 3 hours post exercise. And for me, it's not just a barely noticeable decrease - it's an extremely noticeable long-lasting appetite decrease where I'll often end up skipping meals.

                Do a quick google search for "exercise decrease appetite" for supporting evidence.

                • mister_mister 10 days ago
                  During the exercise the body is in a state of flight or flight[0], the other mode is rest and digest. So during hunger will go away, but the body will want to be able to exert the same or more(because that amount was at least needed), and as such it will start fighting against rapid weight loss by exercise, by increasing hunger, and or slowing metabolism.

                  The reason why this is quite simple, body is unable to see the difference betweenexercise and staying alive in a hostile world. As such staying alive will always be prioritized. If CICO would work then we wouldn't be obesity pandemic[1]

                  [0]https://en.wikipedia.org/wiki/Sympathetic_nervous_system [1]https://pubmed.ncbi.nlm.nih.gov/28292617/

                • px43 10 days ago
                  That sounds neat.

                  For me, after I exercise, I get ravenously hungry and am unable to concentrate for the rest of the day unless I eat a 3-5k calorie meal. I heard it would get better over time, so I did it for a year, one hour with a really good personal trainer, three times a week. It put a lot of strain on my relationships, and I got in trouble at work since I was basically at half capacity, and couldn't get any work done on Mondays, Wednesdays, or Fridays. I did it for a year and it was the same the whole time. I was also told that eventually I would get "addicted" to exercising, but I hated every moment of it up to the very end.

                  After a year of that, I stopped, and regained my sanity for the most part. I didn't actually lose much weight, but towards the end I had gotten some compliments about looking healthier, which was nice, but not worth the psychological tool it took on me. I guess I'm just sitting here desperately trying to not destroy my body further while I wait for some miracle cure for leptin resistance or something.

                  • SamPatt 10 days ago
                    That's rough.

                    3k-5k calorie meal? That's an entire day's worth of calories, for someone really active. Strange your body didn't adapt.

                    • newaccount74 9 days ago
                      3k-5k calories is 3 big burgers with fries, or two pizzas.

                      If GP is eating that much, they are very overweight. You don't burn that much calories during exercise, unless you are running a marathon (which I would not recommend doing 3 times a week).

                      • px43 7 days ago
                        3k-5k isn't a normal day, it's what happens during a binge. I would almost never do that after a workout, I would usually just writhe in pain from the hunger for the rest of the day. I rarely go over 2k calories during a normal day, but after a one hour workout, 2k calories doesn't even slow me down.
                        • newaccount74 1 day ago
                          Interesting, thanks for following up and sorry for making assumptions. It seems we're all different. After a one hour workout I do get hungry, but not that hungry. I wonder if it's just different between people, or if the type of workout makes a difference -- I usually run or ride a bike at medium intensity, maybe it's different if you lift weights or do something more taxing?
                    • sasawpg 9 days ago
                      I would be writhing in pain if I attempted to consume 3-5k calories in a sitting. I consume a lot of calories on basis that I also burn a lot cycling, but nowhere near that in a sitting. Even 5k/day for me would be painful.
                      • SamPatt 9 days ago
                        I can consume 3k a day eating clean, but no more.

                        Eating all that in one meal would require some extremely unhealthy eating, for me.

                        I know sumo wrestlers and other extreme athletes are capable though.

              • watwut 10 days ago
                First, this heavily depends on how exactly you exercised and on your actual diet. Bulking makes you hungry. Mild cardio or runs makes you less hungry and less likely to just eat crap.

                Second, your body is rebuilding and healing itself from micro injuries, so eat proteins if you are hungry at that time. That does not mean your dinner then has to be exactly the same as before, you just have to shift when and what you eat.

        • ohgodplsno 10 days ago
          A part of that weight gain is caused by no longer burning let's say an additional 500 calories a day from cycling, another part is due to lack of activity and muscle atrophy lowering your base metabolic rate. And all of this accounts to one thing: you eat too much for a sedentary lifestyle. Cycling just allows you to compensate.

          So, sure, exercise helps at a certain point. But, take into account:

          * If you're fat, your base metabolic rate is insanely high. Obese people are easily at 3000+ calories needed _just_ to maintain that mass.

          * If you're fat, it's going to be almost impossible for you to do sessions where you burn 500 calories, simply because you're out of shape and possibly exercising injures you. Running isn't exactly good on your knees if you're overweight. Realistically, you'll do 200-300 cal sessions, at best, every day.

          * If you're fat and you manage to burn these 500 calories... Good job, but that's less than 20% of your daily intake. Not eating something is infinitely more simple and efficient.

          Our bodies are incredibly efficient at exercising without using lots of energy. Unless you do it for long and hard enough that you reach huge numbers of calories burned, diet is the most important component of losing weight.

          • sasawpg 9 days ago
            That simply isn't true. Unlike running, cycling at an low endurance pace is quite gentle on your body. Reaching 500kcal/session isn't going to be a problem after a few weeks of getting your mind and body accustomed to biking for more than 15-30 minutes, and chances of injuries will be quite low, especially if you use a stationary bike. You can hit 400kcal in an hour of biking without too many issues. Larger people will generally put out more power and therefore burn more calories.
          • hhmc 10 days ago
            It's 'basal metabolic rate' not 'base', and it's not going to change materially over a year, even with a shift to inactivity.
            • ohgodplsno 10 days ago
              Muscle atrophy from not maintaining exercise for a year will absolutely make your BMR change. In the same way, spend a year at the gym lifting weights and your BMR will absolutely go up, even if at the same weight.
              • hhmc 10 days ago
                Change, but not materially, maybe 5% or something that doesn't really move the needle like the claim of 500 calories.
        • adql 10 days ago
          > It all came off after resuming a normal routine without dietary changes.

          well, doh, if you eat the same and use less you will gain mass. It's not because (lack of) excercise, it's because diet not fitting lifestyle

          Excercises help in burning more calories so you can actually eat some tasty food from time to time without getting fatter and not going crazy from eating only low calorie stuff and that's about the only effect for weight loss...

          • Fricken 10 days ago
            I think what the parent meant by "no dietary changes" is that they didn't have to exercise any special discipline over their diet.

            If I'm exercising regularly with sufficient intensity my appetite will go up, yes, but I still lose weight. For me, when training, keeping weight on is the dietary challenge. It's hard to eat enough!

      • petesergeant 10 days ago
        I think it’s safe to assume that many inactive people start to exercise because they believe it will help them lose weight, however
        • Scarblac 10 days ago
          I find changing diet much easier when I'm also workig to get into shape at the same time.
    • mindhash 10 days ago
      such an important point here. The benefits of exercise are maximum when you start from a sedentary life. You will hit plateau at some point and then one has to re-think the plan.

      I am doubtful that just 10 min exercise over a few years will get you in a better shape.

      Another factor greatly ignored is HRV as key indicator of recovery and response to an exercise. Andrew Flatt (1) is a researcher and has been studying his cardio fitness through HRV for over 10 years. His observation is 10 sec high intensity + 50 sec break in between for 10 minutes improved his hrv. He also thinks 15000 steps contribute to better HRV as good as athlete level.

      While there are plenty of questions about 10k steps, what if 15k steps do the trick?

      In general, I think since HRV and VO2 max are trackable using hand-held and would be best parameters to track usefulness of an exercise over time. It is always likely that an exercise works at some point and doesn't at other. Possibly because you are more fit now or you have other life stresses dragging you down.

      In my experience, a lot of these studies are not reproducible. Because every person is different and context is different too. Genetics add another layer to this. Best is to keep track of your own parameters and try things out.

      References: [1] https://hrvtraining.com/

      • autoexec 10 days ago
        > such an important point here. The benefits of exercise are maximum when you start from a sedentary life. You will hit plateau at some point and then one has to re-think the plan.

        I'd bet that by the time they end up hitting that plateau it'll be a lot easier for someone who has been sedentary to up their game than it would have been if they'd started a more difficult and time consuming workout from the start. Easing into being more active seems like a really good thing and one that might make it easier for someone to start exercising and stay with it long term.

      • gadders 10 days ago
        > such an important point here. The benefits of exercise are maximum when you start from a sedentary life. You will hit plateau at some point and then one has to re-think the plan.

        They call it the novice effect in strength training. Also why you have to pretty much ignore any strength training research done on untrained individuals (unless you are an untrained individual).

      • KronisLV 10 days ago
        > The benefits of exercise are maximum when you start from a sedentary life. You will hit plateau at some point and then one has to re-think the plan.

        I've noticed something similar. In the countryside, I usually exercise when it's warm outside and track my weight and how much I do each day.

        After the winter is over, I start at small amounts of exercise (a few km of running, a small amout of sit ups, push ups, pull ups) and it always feels like initially I drop 3-4 kg of weight rather easily but then it almost plateaus, even if I increase the exercise amount.

        Regardless, it's probably worth it in the long term for overall wellbeing. Just an anecdote, but personally it feels like exercise increases how much energy I have (including how tolerable it is, the first weeks when starting again are always miserable).

        • bratwurst3000 10 days ago
          Sidenote. 60% of natural Musclemass someone can gain can be gained in half a year. Then its plateu. Maybe fat burning is the same.
          • seper8 10 days ago
            source? sounds like bs
            • bratwurst3000 10 days ago
              Sorry cant find it. But here a little calculation. Someone who is 180cm has 80kg of lean mass potential. Someone who isnt trained but lean would be around 65kg or so. So 15kg muscle to gain. If training correctly this person can gain 1-2 kg of muscle per month. So 6 month max 12kg muscle. Getting more muscle with training aint the hard part. Not getting fater while training for mass is the problem
      • notyourday 10 days ago
        > VO2 max are trackable using hand-held

        VO2 max is not trackable via hand-held. VO2 max tracking at this point requires going to the lab, putting on a mask that collects expelled gasses and getting on a treadmill. Neither resting heart rate nor peak heart rate track VO2 max.

        • mindhash 10 days ago
          Agree, you wont get exact numbers but ignoring the absolute values one can see differences over time to see whats working. When it comes to these numbers i have learned that you dont focus on absolute values but watch them change
      • mindhash 10 days ago
        My recommendation will be to track HRV (1) and do the high intensity only when you are on or above your baseline. This is to avoid unexpected side effects of HIIT. If you can't get a hrv tracker then best to keep track of your heart rate recovery. It is common to see heart rate stay high after the exercise, it should return to normal in a few hours (3-4 hours). if not then you are over doing it.

        1 - Apps like Elite HRV, hrv4training or Devices like Garmin (watch), CoreSense (Elite HRV), Scosche Rhythm+, polar or garmin chest wrap.

    • bjornsing 10 days ago
      > It's 8 minutes, not one minute

      > 3x8 minutes of higher intensity exercise

      Not exactly (unless I got something wrong): ”SIT involved 3x20-second 'all-out' cycle sprints (~500W) interspersed with 2 minutes of cycling at 50W”.

      • petesergeant 10 days ago
        This comment does the maths: https://news.ycombinator.com/item?id=34515924

        In fact, it’s 10 minutes not 8

      • geraldwhen 10 days ago
        50W is nothing, and 500W isn’t really a sprint. For an adult male, you should be pushing 1000-2000 over 20 second sprints.

        Walking slightly uphill is probably more intense than a 50w bike.

        • alistairSH 10 days ago
          50W is barely moving on a bicycle.

          But 500W is a significant effort for an untrained person, particularly somebody of smaller stature.

          FWIW, I'm an avid recreational cyclist and my 1-hour power fluctuates in the 250W-280W range at 68-70kg body weight. My all-out sprint power is over 1000W, but not by much. 2000W is enough to win elite sprints, both on the track and on the road.

          • AtlasBarfed 10 days ago
            Mario Cipollini: 1943 watts. Although that's probably the max reading from possibly a minute long sprint, depends on the course. There's probably slightly uphill sprints that would have even more max wattage potential since top pro sprinters on flats are probably maxing out what they can neuromuscularly coordinate on a 53x11.

            But anyway, if you know who that is, you'll know that 2000 watts is not a common max output.

            Edit: Ok I was a 320 watts for 20 minutes guy a few years ago, I'm probably about 250 watts for 20 minutes guy now. I just did this workout, probably in the 500-600 watt range for the 20 second surges, and it was surprisingly hard.

          • sasawpg 9 days ago
            He talks about 20 seconds, that's quite the length to hold 1000W+ on. Not to mention repeat it multiple times with 2 minutes of recovery, which is nowhere near enough for untrained or trained athletes unless you dedicate a significant amount of your recent training on sprints.

            FWIW, I'm in a similar boat, my FTP currently is around 275W, granted I'm smaller (62-64kg), but I am still a long ways away from holding 1000W for 20 seconds.

          • geraldwhen 9 days ago
            I routinely workout with college athletes or former athletes so perhaps my data is skewed on the top end.
        • TomK32 10 days ago
        • oezi 10 days ago
          I don't think so.

          Reading the power charts from https://intervals.icu of 43,000 male cycling enthusiasts:

          - 70% of cyclists are able to sustain 500 W for 15 seconds

          - 50% of cyclists are able to sustain 500 W for 30 seconds

          Only the top 5% cyclists have an average 15 second power exceeding 1000 Watts.

        • bjornsing 10 days ago
          So? If the article says 50/500W then I’d say that’s the best objective description of the effort level.
          • sebastianz 10 days ago
            > So? If the article says 50/500W then I’d say that’s the best objective description of the effort level.

            It is an objective description of the power they produced. NOT their effort level. Their effort level would be established via their BPM, perceived extersion, lactate levels, etc etc

          • oriolid 10 days ago
            The question is whether 500W counts as high intensity, and whether the results are applicable for people whose high intensity is 2 to 4 times higher than the test subjects. I have to admit that I didn't read the linked article, but previous similar ones had the low intensity reference at so low intensity it shouldn't be a surprise to anyone that it didn't produce any results.
            • bjornsing 10 days ago
              The surprise here is that it did produce results. So I’d say the lower the intensity the more interesting the result is.
        • sasawpg 9 days ago
          My all-time high for 20s is 863W. I don't think you understand what it takes to push 1000W for 20 seconds, not to mention 1500-2000W.
    • throwaway292939 10 days ago
      If you're completely out of shape, going at HIIT level intensity is also risky.

      Better to build some kind of baseline before jumping into the deep end.

      • antupis 10 days ago
        It is not risky but it is hard and I rather do low intensity running 60 minutes than 8 minutes HIIT.
        • Existenceblinks 10 days ago
          It is absolutely risky. Easily black out.

          EDIT:: added my experience

          I was riding mountain bike, and went to competition here and there. And then I stopped for many months, got back and rode the same speed. For real I thought I was going to die, it was almost a black out and panic. Never again risking with "coming back with intensive training" .. just no.

        • matsemann 10 days ago
          It is risky. People push themselves too hard to keep up and end up with rabdo. (Edit: I was thinking more of a normal HIIT class, not the 1 minute one)
          • scott_w 10 days ago
            This is a criticism of cross-fit specifically and not HIIT workouts in general. I'd personally not recommend this training to newcomers but that's because I think the study is total bunk, not because I'd be worried about an injury.
            • FartyMcFarter 10 days ago
              Crossfit is bad for most people for other reasons as well. For example, look at how they do pull-ups [1]. It's basically a fitness meme at this point - they use form that doesn't encourage general strength, just swinging around and putting pressure on the arm/shoulder joints on the way down, for the sake of increasing competition rep numbers. This seems utterly pointless unless you really care about winning Crossfit competitions [2].

              [1] https://www.youtube.com/watch?v=4PWvepZMZ7E

              [2] https://www.youtube.com/watch?v=lEe-loVKOOM

              • matsemann 10 days ago
                No, "most people" wont do that kind of pullups in crossfit. Yes, those doing competitions are optimizing for something else (reps) than general strength. But most of those doing crossfit actually focus on the general strength.
              • matwood 10 days ago
                I feel like there is Crossfit the brand and crossfit the idea of group fitness helping people be accountable, learn proper form, etc... The former is garbage, while the later can be good.
          • newaccount74 10 days ago
            Does that really happen for 3x 20sec max effort on a stationary bike?
            • scott_w 10 days ago
              No, this is a common theme I see. People who know nothing about exercise take real medical things that happen to people who massively overtrain and assume it can happen to a regular unfit person exercising for 10 minutes a day.

              For the 3x20s intervals, the max effort of a person is far, far, below the max effort that, say, I can put out (as a trained cyclist). I strongly doubt the people doing this were actually pushing the 500W for 20s that I saw bandied in another thread. They're more likely pushing 200W and tickling 300W for a few seconds. This is still a high perceived exertion (though lower absolute kcal expenditure), so it's a good effort on their part. But they're unlikely to black out or cause major muscle injuries beyond feeling a bit sore in the morning.

              • matsemann 10 days ago
                The rabdo I'm talking about doesn't just happen to people that overtrain on a regular basis. It happens often to beginners doing their first workout at a gym being pushed to hard. But I agree, for 1 minute total effort it's probably not a risk. My comment was more in the general sense of giving untrained people high intensity workouts, especially in a group context where they take it too far (like crossfit).
                • snovv_crash 10 days ago
                  I've never seen rabdo documented as coming from a first workout. Usually it's from overtraining 3-4 days in a row while being dehydrated, or it's due to an ultramarathon runner pushing through the pain on their 100 miler in a desert, or (much more likely) it's a car crash crush injury.
                • matwood 10 days ago
                  > often

                  Citation needed. Which is the point of the person you're responding to. For an untrained person to even get to what is considered 'high' intensity in their first workout is not common.

                  I do all sorts of training with trained and new people alike and have never seen rhabdo in person. I know it can happen, but I think the stories stick out because it's so uncommon.

                  • matsemann 10 days ago
                    > Citation needed.

                    But no citation needed from your personal experience of never seeing it..? I think you're reading waaaay too much into what I'm saying.

                    • matwood 10 days ago
                      Yeah. If you're saying 'often' then people who work out and/or train people a lot should have a decent likelihood of seeing it.

                      I know it happens because I've read articles of it happening. But the way people bring it up any time a fitness discussion occurs is a meme at this point.

                      • matsemann 9 days ago
                        My point was that it happens more with beginners, so an experienced not seeing it often is expected..

                        Btw here is a local source. Three people got it from a group session. The doctor in the article says it happens about 400 times a year in little Norway, and that the group most often affected is people that used to be fit many years ago, and then start off too hard.


                        • scott_w 9 days ago
                          This is a common case I see of misusing statistics without really understanding what's happening. I can't read Norwegian but I'll take a stab at what's happened here (based on my knowledge of other articles and having 20 years of personal experience of fitness training).

                          - This wasn't one group session but repeated sessions of HIIT back to back (maybe even daily).

                          - There wasn't sufficient rest between sessions.

                          - Some of these were older (50+) patients.

                          The most important part is the repeated sessions. Doing a single session of HIIT pull-ups or sprint intervals on the bike aren't going to cause major muscle damage, even in an untrained person. Doing 5 days back-to-back, repeatedly going beyond failure (something Crossfit is notorious for), with improper form, are what causes the issue.

                          • matsemann 9 days ago
                            This was a new type of training session in that gym. One of those affected was a 26 year old, the two others ~40. I don't get why you feel the need to make up causes.

                            Most of what I read points out that it's more likely to happen to untrained individuals. It may be because they start to hard over multiple days, but that's not going against what I've said multiple times: that it's a high risk for untrained individuals jumping into high intensity training. _That's_ my point.

                            • scott_w 9 days ago
                              > that it's a high risk for untrained individuals jumping into high intensity training

                              This statement erases all nuance in the real world data and experience of anyone involved in training.

                              You need to differentiate between one HIIT session and repeated HIIT sessions without recovery. The former doesn't cause injury in the vast majority of individuals. The latter is known to cause injuries in everyone trained or untrained.

                              You also need to control for what the HIIT session is. If it's spinning on a stationary bike for 2 minutes, an untrained individual generates nowhere near enough force to then injure themselves. If you're putting a set weight on a bar and asking them to shoulder press it, that's self-evidently completely different.

                              Yet, in your argument, they're exactly the same.

          • geraldwhen 10 days ago
            The only person I know who got rabdo was not drinking enough water daily and supplementing creatine.
            • antupis 10 days ago
              yup personally I don't know anybody who have got that when training and what I have heard it is usually not enough water + some sketchy supplements like https://en.wikipedia.org/wiki/Hydroxycut .
            • FartyMcFarter 10 days ago
              What does creatine have to do with it? If anything, creatine seems to reduce the risk, by reducing the amount of muscle damage:


              "Overall, the available data strongly suggest that creatine supplementation prior to an endurance exercise challenge reduces muscle damage and inflammation in athletes, both of which would predict a lower risk of rhabdomyolysis, not a higher risk."

              • geraldwhen 10 days ago
                Creatine is processed by the kidneys, which exacerbated or caused the rhabdo. The kidneys were too stressed to handle the muscle breakdown.
              • snovv_crash 10 days ago
                Creatine gives you extra strength which could allow you to push your muscles harder.
    • PragmaticPulp 10 days ago
      > The people in the study were out of shape to start with

      > In conclusion, if you're out of shape, you can improve a limited number of fitness measures

      While this isn’t going to make athletes change their exercise programs, it’s a great reminder that if you’re sedentary you can get significant health improvements by doing literally any exercise at all. Some times dramatic improvements.

      Exercise doesn’t have to be complicated. Doing anything is significantly better than being sedentary.

    • newaccount74 10 days ago
      I think it was 10 minutes in total:

      2min warmup

      20sec max effort

      2min recovery

      20sec max effort

      2min recovery

      20sec max effort

      3min cooldown

    • Existenceblinks 10 days ago
      Coming back from out of shape with intensive exercise doesn't sound good to me. I often start with cycling for 25km x 3 days. Walk 10 km x 2 days rest 2 days. Something like this and then start to run / basket ball / swimming etc.
    • marcosscriven 10 days ago
      I'm just imagining the scene in There's Something About Mary.

      "No! No, no, not 6! I said 7. Nobody's comin' up with 6."

    • kilgnad 10 days ago
      >In conclusion, if you're out of shape, you can improve a limited number of fitness measures just as much doing 3x8 minutes of higher intensity exercise as much 3×45m less intense exercise over 12 weeks

      Make no mistake. The metric HIIT improves are limited, but these metrics are the ones we anecdotally use to observationally to separate people who are fit and people who are unfit. In other words, the people who we consider to be "fit" when exercising tend to be extremely high in these specific metrics.

      I've been doing HIIT almost exclusively for a decade. You may still have high cholesterol after doing HIIT, but your VO2 max will be through the roof. And not just a little. This isn't just for people who are unfit, it can bring those specific metrics to near athlete level performance if you go at it consistently.

      From a more laymans perspective, VO2 max is the main metric that this type of exercise improves which dramatically improves your observed athleticism in sprinting, running and almost every sport that involves endurance.

      It won't help you lose your gut or lose weight though. This is just my own anecdotal observations after a decade of using HIIT as my main exercise.

    • TheRealPomax 10 days ago
      If we're going to dismissively summarize, shall we at least summarize it correctly?

      > The SIT protocol consisted of 3x20-second ‘all-out’ cycling efforts against 0.05kg/kg body mass, separated by 2 minutes of low-intensity cycling (50W).

      You're right, that's not one minute. That's 20 seconds high intensity spinning spaced out with 2 minute "just regular biking" sets. Turning that into "it's 8 minutes, not one minute" takes some doing. Anyone with a home exercise bike can comfortably repeat this regime.

    • bitL 10 days ago
      10 years ago I started doing HIIT via the 7-minute workout while initially out of shape. The first month was horrible, then my body substantially improved, I stopped being lactose intolerant (could suddenly drink a gallon of milk a day without any issues), then I could stack 2 HIITs and later 3 HIITs in a row, then I could push more and more reps in each 30 second interval, achieving like 4-6x improvement compared to when I started and my fitness exploded.
    • l33tman 10 days ago
      "SIT involved 3x20-second 'all-out' cycle sprints (~500W) interspersed with 2 minutes of cycling at 50W, whereas MICT involved 45 minutes of continuous cycling at ~70% maximal heart rate (~110W). Both protocols involved a 2-minute warm-up and 3-minute cool-down at 50W."
    • watwut 10 days ago
      The measures that improved are more important then body mass itself. Body mass is an aesthetic measure. The improved measures were directly related to the health. And "fitness" itself is measured by performance, not by how you look like - which would make it third measure.
    • kirso 10 days ago
      This is a common misconception for a lot of studies. The selection bias is strong when trying to make us eat fake meat, nutritious sugar, keto diets etc. etc.
    • seeingfurther 10 days ago
      No! No, no, not 6! I said 7. Nobody's comin' up with 6. Who works out in 6 minutes? You won't even get your heart goin, not even a mouse on a wheel
    • ianai 10 days ago
      Is HiiT really a good idea for people with increasing levels of being out of shape? That sounds like a recipe for doing way too much way too fast and getting injured.
      • tootie 10 days ago
        You can just vary the intensity. The general approach is go as hard as you can for brief bursts then back to a comfortable pace to recover, then burst again. Your peak burst may be pretty slow at first, but if it gets your heart pumping, then you're doing it. That peak should just go up as you train and build your strength.
    • MuffinFlavored 10 days ago
      What if you aren't super out of shape? Do the results translate/is the "hack" too good to be true?

      Working out for 45 minutes a day isn't fun

    • Dwedit 10 days ago
      Seven Minute Abs
    • lynx23 10 days ago
      Or you just eat less, which is probably going to change your body mass without exercise :-)
      • dkdbejwi383 10 days ago
        But still have low cardio fitness. A healthy body needs exercise and a good diet.
        • lynx23 10 days ago
          Question is, how to get that "exercise". I am going to be downvoted, but I am convinced sex twice a week is more or less sufficient for the "exercise" part.
          • scott_w 10 days ago
            Because it's not even close to sufficient. Your "conviction" doesn't hold a candle to established medical knowledge.
            • lynx23 10 days ago
              "Established medical knowledge", don't make me laugh! According to that, I should have a countable number of covid deaths in my family and friend circles, even our (ex) chancellor told us via media that everyone will know someone who died due to covid. Apparently, I am not everyone, and my friends apparently are not everyone either.

              "establish knowledge" my ass.

              • scott_w 10 days ago
                Ahh so you’re a Covid denying loon. This makes a lot of sense now.
                • hanifc 10 days ago
                  That seems like a very uncharitable interpretation of what the poster said. I interpreted it as "Medical studies and statistics don't always map perfectly to the individual case."
                  • scott_w 10 days ago
                    I think I should remind you that you’re defending someone who is “convinced” having sex twice a week is sufficient exercise.
          • dkdbejwi383 10 days ago
            I doubt it. It doesn’t target enough muscle groups and you ideally need some variations of push/pull/lift as muscle groups are engaged in different ways for different motions.

            Probably not fantastic for cardio either, ideally you want a lot of training in zone 2 for endurance and some training at max for power.

            • lynx23 10 days ago
              Everyone their own. I prefer to feel fine without a training regime and without assuming that everything I do is insufficient. I feel very good with that attitude and approach. However, I am not overweight, so its easy for me to feel that way.
              • scott_w 10 days ago
                Smokers feel absolute fine for years. Until one day they don't.
                • lynx23 10 days ago
                  Humans feel absolutely fine for years, until one day, they die.
          • bt4u 10 days ago
      • gadders 10 days ago
        I wonder what would be best long term - an obese person that exercises or a "skinny" person that doesn't?
  • twawaaay 10 days ago
    Everybody knows that high intensity exercise does more than low intensity ones per hour invested. At least in running world.

    The issues are, and especially when you are out of shape:

    * adherence -- it is difficult to keep people do hard, high intensity exercises regularly. Part of being a runner is learning to deal with pain but people who are out of shape are almost by definition new to this and are not yet accustomed to pain.

    * injuries -- especially when you are out of shape, the goal should be consistency over quality. Any injuries will immediately put you out of your high intensity training. And high intensity training with out of shape people is a recipe for lots of injuries.

    * volume -- while you can do a lot more per minute on high intensity exercise, you can do a lot more low intensity volume. You can quickly and safely build up to be able to do half an hour of slow jog a day even if you are overweight and out of shape.

    * recovery -- high intensity exercises have high recovery requirements. Do out of shape subjects know how to massage their muscles? How to stretch? How long to recover? Recovery will further cut the volume of training. An out of shape person may need 3-4 days of recovery after a short but hard, intense interval session. Normally, this is filled with low intensity running and intense sessions are limited to once a week to give time to recover.

    Even elite runners recognise how dangerous it is to do large volume of high intensity exercises and there is very popular, successful movement now to almost exclusively low intensity exercises and reserving high intensity mostly for the last stretch before the event. The main goal of this is to ensure injury-free training.

    So if I was taking care for out of shape patients and prescribing training regimen I would still tell them to do, for starters, easy, comfortable jogging rather than any high intensity exercise.

    • galacticaactual 10 days ago
      > Everybody knows that high intensity exercise does more than low intensity ones per hour invested. At least in running world.

      No. This is actually wrong. You should read Scott Johnston's "Training for the Uphill Athlete" to understand why.

      • dkarl 10 days ago
        I read that book, and as with most other sources of information about endurance training, I found it to be very focused on the situation where people are limited by their recovery budget. I couldn't tease out what the guidance would be for someone who only works out 3-4 hours per week. There would be physiological explanations of the unique value of low-intensity training, and I would think, "Sounds like this applies to everyone," but then there would be an implicit reference to overtraining. Eventually I came to the conclusion that everything in the book assumes that you're training so many hours per week that even if 70% of it is low-intensity, you're still stretching the limit of your ability to recover.

        I haven't made an exhaustive search or anything, but I've repeatedly been frustrated by this pervasive assumption when looking for information about endurance training. I guess this makes sense, because even the amateurs I know who love endurance sports work out 10+ hours per week. I just don't love it that much.

        I've found one single piece of advice (and again, I haven't made an exhaustive search or anything) in a podcast interview[0] with an expert on and advocate of polarized training for cyclists. In response to a listener question, the expert said that if he only had four hours per week to train, he would "just hammer... and hope for the best," meaning train as intensely as he was able.

        [0] https://www.youtube.com/watch?v=Ju3McjlSoAg&t=702s (11:42)

        • galacticaactual 10 days ago
          Perhaps your next read should be Mark Twight’s essay aptly titled TNSTAAFL.
    • paulcole 10 days ago
      > Everybody knows that high intensity exercise does more than low intensity ones per hour invested. At least in running world.

      “Does more” is hella vague. As a 40-mile a week runner I find that low intensity runs “do more” for me because they’re more relaxing.

      • twawaaay 10 days ago
        I used it in a "scientific" way. If you were able to put the same person to do two exercises, one 60 minute easy run and second time 60 minutes tempo run (and possibly also time travel inbetween both sessions so they are in the same state at the start) you would measure that in the universe where you did the tempo run you would improve your fitness more (unless you were somehow injured/overtrained and not ready for the tempo run).

        This is where the part "per hour invested" comes.

        Most people can't do an hour of tempo run every day without getting themselves overtrained and injured. And if they could do it physically, it would be enormous mental challenge.

        Switch to most of us like you and me -- an easy run provides most of the benefit per hour invested but in a sustainable way, meaning you will be able to invest more hours and do it consistently. And you will be more likely to stick to do it every day if you find it refreshing and relaxing rather.

      • infamousclyde 10 days ago
        I mean, I think I understand what they're saying. A thirty minute tempo will develop your aerobic capacity more than a thirty minute easy run-- more or less analogous to progressive overload in weightlifting. That's not to say that you can't grow/improve as a runner without challenging sessions, but I imagine the rate of improvement would be significantly lower. Pro runners would be doing as many workouts as possible per week if recovery weren't an issue!
  • arthurofbabylon 10 days ago
    In personal experience as a dedicated rock climber (traveling full time for half of the last 15 years), I can easily conclude that bursts of intense exercise accomplish a lot more for health and fitness than prolonged, more gentle workouts. Intensity readily builds muscle mass and coordinates muscle fibers, while fostering feelings of clarity and joy. It’s just the easier pathway to “being fit.”

    Climbers train for intensity. One can easily convert high-intensity fitness to low-intensity but prolonged fitness. The other direction does not happen. High-intensity and short-burst fitness is more malleable, capable of becoming any type of fitness. Ie, a climber with bouldering fitness transitioning to sport climbing will take just 2-3 weeks to attain good results, while a sport climber transitioning to bouldering will take at least two months. Boulderers and sport climbers can instantly perform on multi-pitch routes, without a transitional period. The intensity gradient from intense/short to gentle/prolonged is bouldering -> sport climbing -> multi-pitch.

    However, I have never been at peak climbing fitness without daily walks. The assumption I have always held is that walking resolves problems (much like what sleep accomplishes for tissues, immune responses, emotions, memory, and cognition). You’re walking, blood is flowing, the whole body is coordinated, you’re breathing through your nose, you can think… it’s integrative. Humans are designed to walk.

    • TheAlchemist 10 days ago
      This may work in climbing, but as far as I know, it doesn't really work in cycling or running.

      Yes, you should do a bit of high-intensity, but also ~80% of your training in those disciplines should be rather low intensity. Basically one does not work without the other.

      • dkarl 10 days ago
        > Basically one does not work without the other.

        This is true for high-level competition, but it's overly absolute for the rest of us. They both definitely work to some extent.

        I think for the general public, the balance of high and low intensity training has to take into account how much time people are willing to dedicate to it. A friend of mine and I backpack together, and we both dedicate much more time to exercise than the average person, but much less time than a dedicate amateur. Call it three hours per week on average. My friend does exclusively low-intensity endurance training, because he dislikes anything else, and I do mostly strength and high-intensity training, for the same reason. I think it's plausible that given the limited hours we're willing to put in, my high-intensity training prepares me better for long-duration, low-intensity activity.

        The data we have about endurance training comes from studies and dedicated athletes. A lot of people fall into the middle ground: not sedentary, and willing to put in more time than a study participant, but also not putting in 10+ hours of training per week like a competitive endurance athlete.

      • Fricken 10 days ago
        A practice amongst Olympians across many disciplines is to spend the first year of their 4 year training cycle focused exclusively on building a foundation of strength.
    • fingerlocks 10 days ago
      Going to have to disagree. I’ve bailed from a few Yosemite big walls because a partner lacked the endurance to climb 16-20 hours straight. These were 5.13 sport climbers that were too bonked to jumar the rope.

      Nope, you can’t run a climbing marathon unless you train for it.

    • nmca 10 days ago
      Isn't this just a different thing? Bouldering builds peak strength, not really intensity in the sense it's meant here? Max hangs do not translate to watts you can do for a minute on a bike, right?
      • geraldwhen 10 days ago
        Bouldering requires leg strength and max effort output over a minute timespan.

        Heel hooks, slab, arete, bat hangs are all going to tax your lower body, and a good boulderer can put themselves in hell for a limited timespan, as it’s required for many problems. Climbing is so much more than pull up and grip strength.

    • saiya-jin 10 days ago
      > One can easily convert high-intensity fitness to low-intensity but prolonged fitness.

      This ain't truth even though I get where you are coming from. Otherwise ie best sprinters would be automatically best ultra marathon runners. Guess what - they are not even trying to compete there, its just different sport, their bodies are simply not accustomed by training for that and they would be pretty bad at it.

      Climbing, however good sport that is (apart from people dying from time to time mostly due to human errors but not only), ain't the best indication of this - if you are an elite climber, you don't go out and do ie 10-hour continuous hard scramble/easy climb. No, you focus on those hard routes, ie on project for a week or month. Yes you have decent endurance on those easy climbs but that comes from overall fitness that top climbers simply must have

    • fransje26 10 days ago
      Maybe the walks had the same contribution to your fitness as light "recovery training" days have? Where the low intensity effort actively helps your body & muscles to recover from a previous training in a more efficient way than a training-free day would?
  • chkgk 10 days ago
    The study apparently only involved male participants. The control group consists of 6, the two treatment groups of 10 and 9 participants. The total N of the study is 25 participants. They conduct a one-way ANOVA on the interaction of time and treatment group indicators. I conclude that the study is woefully underpowered. I do not trust the apparent significance of their results.
    • danieka 10 days ago
      I really don't understand statistics. My interpretation of "the study is under-powered" is that since the study has so small groups it will be difficult to find any result that is statistically significant. But wouldn't that mean that for any effect to be significant the effect size would have to be huge?

      My hunch is that if you have a large enough group even very small effect sizes will be significant, but in small groups only the very largest effect sizes will be significant. Or am I simply bad at statistics?

      • notafraudster 10 days ago
        (See bio for my background) All of the replies you've gotten so far are very good and I upvoted all of them.

        In particular:

        cuchoi acknowledges the publication bias version of the risk here. Let's say your average effect is 1 unit with a confidence interval that is 0.9 units at a desired level of confidence. We can interpret this confident interval two different ways: one is that assuming 1 unit is the true effect, then repeated sampling would produce a sampling distribution of estimate effects that span 0.1 to 1.9 at the desired level of confidence. Another is assuming that, say, 0.1 was the true effect, effects as large as the one we see (1 unit) would occur a non-trivial portion of the time. Now, imagine many researchers do this experiment and the true effect is 0.1. Some researchers find negative effects, some find small effects that are not significant, others do larger studies and find small effects that are significant, others find larger effects. Now, imagine the journal will only publish effects that are both statistically significant and substantively interesting. The only person that submits for publishing is the version of the study that finds the large effect (1 unit). cuchoi is very correct to suggest that when your design can only find large effects, the published effect will likely be overestimated.

        fpoling and sandgiant highlight the sensitivity risk argument. Suppose that the outcome is heavily sensitive to some confounders (socioeconomic status, nutrition, smoking status, race, etc.) And suppose poor people are slightly more likely to get treatment, just from coin flip chance. Because poverty correlates with both the effect and the probability of being treated (even though you tried to assign randomly), some of the visible effect is the relationship between poverty and treatment, not effect and outcome. There are designs other than simple randomization that try to explicitly deal with known confounders, but they can't deal with unknown confounders. Larger sample sizes mitigate the risk of imbalance of both known and unknown confounders.

        Everyone is doing great!

      • cuchoi 10 days ago
        Under-powered also means that the minimum detectable effect is high (that's why it is harder to get a "significant" result).

        Which means that it is more likely that if you will find an effect only if you are overestimating the real effect. The real effect might not even be detectable!

      • sandgiant 10 days ago
        There might be someone able to better explain this, but one way it could work wold be to say that for small samples any bad assumptions you make (such as variables or measurements being independent) will affect the result more than if you had a larger sample.

        The assumption I make to make this work is that dependencies are more likely to be drowned out by internal variation in a larger sample. So you get to pick which assumption you like better.

      • fpoling 10 days ago
        A simple rule of thumb is that for samples with N < 100 be very skeptical for the results as those can be archived simply by randomness on top of small systematic errors. Proper statistics helps to rule out randomness, but not systematic errors. Which pretty much rules out most of the sport studies.
      • oblio 10 days ago
        I studied this many years ago, but you have formulas for survey sizes based on confidence levels and, if I recall correctly, the number of variables you want to study.

        People publishing these studies should know and use these formulas, but I imagine there's a lot of pressure to publish high impact/visibility stuff so they just go for the cheapest and fastest (aka wrong) approaches some times.

      • wirrbel 10 days ago
        short answer: its complex and there are books on the topic.

        lesser-disappointing answer:

        You have a hypothesis how STUFF works differently when you make an intervention (experiment, i.e. collect data, change something or go to the control group, collect more data).

        Your default assumption is that your experiment won't show a meaningful difference, OR it could show a difference (positive/negative). Now what you observe may not be the reality. Which leaves you with 4 possible situations:

        False-positive, true-positive, false-negative, true-negative

        Most statistical methods used in data analysis take great care to minimize the probability for a false positive (probability our methods yields 'positive', when in fact there is no effect in reality. This probability is the famous 'p Value' (sometimes p Value also refers to a threshold of this probability).

        So when you do certain statistical tests, you receive a p-Value, apply a threshold consideration p<5% for example, this means that you assume that only every 20th experiment where in reality there is no effect results in a 'significant' finding (i.e. a false-positive).

        So naively increasing your sample size will not lower your false-positive probability if-and-only-if your analysis method corrects for it. However the sample size strongly influences the false-negative rate, i.e. a Student t-Test with p<0.05 will with sample size N=3 yield a false-positive with still a 5% probability, which in practice then means, that there is a slim chance to get a true-positive results.

        The criticism here about sample size does from this perspective not make too much sense, however: we need to keep in mind:

        A) There is a whole field of problems about controlling variables (i.e. adding more columns to your data table). Each variable adds another dimension to your problem, and this quickly leads to a 'curse of dimensionality' problem. Is the observed effect explained by your experimental intervention, or is it in differences between your control group and your study objects (sex/gender/socioeconomic status/age/training level/ overall health). Quickly not being able to control for a variable can lead to false-positive results.

        B) complexity of the method at play. The study uses ANOVA (analysis of variance). Its been years that I last looked at it so I am not making statements here.

        C) Crucially: Many methods actually assume Normally-distributed data (Gaussian distribution). However, if you collect data it is rarely normally-distributed, one can use methods for normally-distributed data on non-normally-distributed data because of the "law of large numbers", i.e. mixtures of non-normally-distributed datasets typically tend to end up being normally-distributed. but this does not happen at N=10.

        There are a few finer points to mention here, which is that many HN commenters have a machine-learning background and may be a bit biased against smaller-sample-size studies for multiple reasons that are specific to what they are used to in the machine-learning world. And on the other hand, from my experience majoring in biophysics, many health-related studies on sports and obesity really have low-quality stats and overestimate the predictive power of their datasets.

        tl;dr: I would only conclude from this study that HIIT is better than nothing, not that it is better or worse than other cardio exercise.

        PS: The above text tries to break down complex stuff and thereby by definition contains mistakes.

    • spaceman_2020 10 days ago
      Every time I see a study with a big headline, it almost always has double digit participants.

      Very callous behavior.

      • pbhjpbhj 10 days ago
        First studies with new findings should be small, surely, so we can weed out effects to test with larger studies. The question is whether the larger studies are being done? The incentives are such that democratic governments need to be leading the research, IMO.

        How do we ensure at a national level (because studies probably need to be repeated in different nations) we're doing good science, backing up key results, informing the population what the better ways of behaving are?

    • thom 10 days ago
      Sports science is probably the most unintentionally hilarious branch of statistics.
      • grogenaut 10 days ago
        Everything around nutrition in general... But yeah with sports your throwing in groups of insanely driven outliers. Even more fun is mapping that back on the average human like much of this post is doing. No you should not try and follow Michael Phelps pre Olympics training routine.
    • jasonladuke0311 10 days ago
      I'll do you one better: all of the subjects were untrained. Any kind of training will improve fitness in virtually every single marker that can be measured. Your aerobic fitness will improve from lifting heavy weights. You'll get stronger from running. These studies are totally useless.
  • jonplackett 10 days ago
    All these many studies about 1 minute exercise don’t seem to take into account how long that fitness will last, and how likely you are to get injured.

    I started running about a year ago and the first thing you have to learn is there’s a bunch of body systems you need to improve - heart, ability to use oxygen, removal of lactic acid, strengthening your body so you don’t get injured and can therefore train continuously. Probably others.

    And they all are best adapted by training at different speeds and intensities. So you do some fast stuff and some _really_ slow stuff and some in the middle stuff.

    High intensity is definitely great exercise. It definitely does something that slow stuff doesn’t. But it doesn’t mean you should _only_ do high intensity.

    • rintakumpu 10 days ago
      As a former national-level 10km runner I can very much second this training regimen. However if your starting point is sedentary you are probably better off doing something that you like and can commit to, be it high-intensity or otherwise. Studies like these are important in showing various tradeoffs but shouldn't be used blindly and prescriptively.
      • jonplackett 10 days ago
        Hey - congrats on national level 10k! Very impressive! When you say ‘this’ training regimen, do you mean the fast/slow/in between i described, or the one they talk about in the article? If the article then I’m gonna give it a try anyway!
    • grogenaut 10 days ago
      Agreed. Getting back into shape or higher shape is often focusing on the part of your body current letting you down. A simple loop is you sprint, your legs gas out... Squats or other exercise. Legs strong now, you can't breath hard enough... More core... Now your core is stronger than your legs are. Legs again. Then consider stabilizers (I'm currently unable to squat more till I strengthen those).. etc etc. As I get older I'm learning more and more about stabilizers and tendons don't strengthen as fast as they used to.
  • pocketarc 10 days ago
    The fact that 1 minute of high intensity exercise (in 10 minutes of lower-intensity stuff) is as good as 50 minutes of moderate-intensity training does really put things into perspective.

    What I wonder now is - what if you combine both? What if you do 50 minutes of moderate exercise but intersperse that with that same 1 minute of all-out sprints?

    Is there a bigger benefit, or is it inconsequential?

    And another question, one that I couldn't tell from looking at the page: What about a control group doing 10-minute moderate exercise? It'd be great to compare the 10-minute moderate vs the 10-minute with the high-intensity exercise. Since these were sedentary men, it stands to reason the there's a big amount of low-hanging fruit that might well be captured by the simple 10 minutes of moderate-intensity exercise. I'm sure it won't fare as well as the 50 minute group, but if it's close enough to be statistically insignificant, the conclusion would change to "any exercise is better than no exercise, even 10 minutes of moderate whatever".

    • matsemann 10 days ago
      Note that these were untrained people. I doubt a fit person would get any response at all for such a low load.

      Actually, once you get really fit, you want to decrease the high intensity. Because otherwise it increases your recovery time so much, that the amount you actually can work out is low. Almost all volume a professional endurance athlete does in addition to what a normal amateur does, is low intensity.

      • presentation 10 days ago
        Agreed but untrained people are the vast majority of society so findings like this probably hold outsized value.
    • deafpolygon 10 days ago
      They studied sedentary men.

      > Methods: Sedentary men [...] performed three weekly sessions of SIT [...] or MICT [...] for 12 weeks or served as non-training controls

    • MengerSponge 10 days ago
      It's probably far more beneficial to save the max effort for the very end. Fatigue and lactic acid concentration work in your favor that way
      • matsemann 10 days ago
        It depends. While your total work done might be higher like that, training for longer with the lactic in your muscles also has some benefits. Doing the intensity earlier also increases your heart rate earlier, and it will probably remain higher throughout, which can be a good thing if your goal is to work it.
        • MengerSponge 10 days ago
          Spending more time in Zone 3 is harder, sure, but it isn't more beneficial than spending that time in Zone 2. You're training different metabolic states, and working harder/suffering more doesn't actually matter.
          • matsemann 10 days ago
            Yes. But if we're at the level where we care about zones and total intensity because of recovery, one probably isn't doing a combined workout at all. Either it's a low intensity or a high intensity workout, not a combination of both.
            • MengerSponge 10 days ago
              Plenty of people who care about zones and total intensity do a low intensity session with a high intensity kicker.

              I got the idea from Prof. San Millan: https://peterattiamd.com/inigosanmillan/

            • jeltz 10 days ago
              Not my experience at all. Plenty of people do long runs (2h+) with faster portions. Maybe it turns out it is inefficient but it is a common practice among marathon runners.
              • MengerSponge 10 days ago
                There's a difference between a faster portion and Tabata portion. Mixing in some faster cadences helps keep things interesting even if there isn't a huge physiological benefit.
  • Manfred 10 days ago
    From the abstract:

    > We investigated whether sprint interval training (SIT) was a time-efficient exercise strategy to improve insulin sensitivity and other indices of cardiometabolic health to the same extent as traditional moderate-intensity continuous training […]

    Researchers are not claiming improved overall fitness as the Hacker News title seems to suggest.

    • pocketarc 10 days ago
      True, that seems a bit misleading. But what is fitness if not something that can be measured as "indices of cardiometabolic health"?
      • Manfred 10 days ago
        I think fitness encompasses everything that makes you physically capable. Cardio metabolic is just one part of that.
  • xarope 10 days ago
    As others below have pointed out, the study specifically targets certain markers, and these markers do not encompass "fitness" as we would expect.

    I learnt the lesson a long time ago that you need to train long and low as well as short and hard, so I'd like to repost this article from Mark Twight (if anybody has a better - or more original, link, please feel free to post it): https://equipesolitaire.com/blogs/discourse/85824260-no-free...

    • Fricken 10 days ago
      The article is directed towards elite, competitive athletes who are already in shape and have a training history. At that level, yes, of course there is more to it than a few short sprint sessions each week.

      For about 15 years I've been relying on HIIT to go from being out of shape to in shape as quickly as I know how. Going from in shape to top fitness, and progressing from there is more involved, and sport specific.

      • moneywoes 10 days ago
        What was your protocol?
        • Fricken 10 days ago
          Last few times I've done it was sprinting on stairs. Typically I'll do a 10 minute warm-up, and then 3-8 sprints, 20-40 seconds each, with ~3 minute rests in between. However I'm not super particular about protocols. I just go out, redline my heart rate a few times and call it a session.

          Last summer I was sprinting stairs every 3 days for a month to prepare for a week of multi-pitch climbing (with huge approaches) in the Canadian Rockies. I whipped myself into pretty good condition for the trip and my body held up, but it wasn't until after that week of climbing mountains every day that I felt like I was in properly awesome condition.

          • xarope 9 days ago
            Please excuse the bluntness, but I find it hard to believe that you only trained sprints every 3 days (so 2-3 times a week max) to train for huge approaches and multi-pitch climbing (I'm a trad climber and mountaineer too).

            I assume this was not done in a vacuum, but also included numerous days of climbing and approaches as well, so probably 3/week of climbing, other low intensity work, as well as your then added 2-3/week of sprints.

            And yes, I agree with your last statement, after 3 weeks in the mountains acclimating for a 7000m peak, even though we got snowed out and never summited, when I got back to ground zero I felt like my lungs and legs were invincible (for about a week, then the bottom dropped out and I went back to normal again!)

            • Fricken 9 days ago
              I've been in condition for these things in the past, but over a winter of mostly just walking, light cycling and gym climbing my legs and cardio had suffered.

              It's explosive training, my muscles hurt afterwards, and I needed 3 days to recover. Over the month of stair sprinting every 3 days I regained about 5 pounds of(what I presume is) leg muscle.

              The premise behind it is that the high intensity stress of my short sprint sessions is effective way to prepare myself for the all day but lower intensity stresses of big climbs with big approaches, for my heart as well as my legs.

              My calves and achilles tendon took a beating on the trip, one thing I wasn't well prepared for was all the standing on my toes.

              I've relied on a period of sprints, either on stairs, flat ground or on a bike, to whip myself into condition a half dozen times over the past couple decades. At 46 I find I don't snap into fitness as quickly as I once did.

              And I don't live anywhere near big hills, if I did I would train on them more, but not at the full expense of running sprints.

  • thejackgoode 10 days ago
    The title is not really honest, it’s a 10 min “commitment”. If you frame it correctly, the result isn’t that surprising
    • Prcmaker 10 days ago
      I'd like to understand where this title came from. The title within the article, while longer, seems much more reasonable a statement:

      "Twelve Weeks of Sprint Interval Training Improves Indices of Cardiometabolic Health Similar to Traditional Endurance Training despite a Five-Fold Lower Exercise Volume and Time Commitment"

    • niemandhier 10 days ago
      I disagree.

      The time durations differ by factor 5, more so it’s 1 min 500w + 9 min 50w compared to 45 minutes 110 w.

      To frame that: Physical Labour can be sustained for longer durations at about 75w, and you cannot safely jump from 500w to resting state without a cooldown.

      So imho the paper delivers what it promises.

    • lanewinfield 10 days ago
      Sure, but the high intensity is 1 minute total.

      2 min warm up

      20 sec sprint

      2 min maintain

      20 sec sprint

      2 min maintain

      20 sec sprint

      3 min cooldown

      • cesaref 10 days ago
        There is no control of not doing the 20 sec sprints, so i'm not sure how I can conclude that the sprints give the benefit vs the low intensity work surrounding it.
        • lelanthran 10 days ago
          > There is no control of not doing the 20 sec sprints, so i'm not sure how I can conclude that the sprints give the benefit vs the low intensity work surrounding it.


          We cannot tell, from the experiment, how much of a difference each high intensity section in the 10m contributes.

        • niemandhier 10 days ago
          Control would not be safe, going from 500w to idle can cause cardiac problems. Especially with elevated bmi.
          • balfirevic 10 days ago
            Control would be doing 10 minutes of low intensity.
        • testmasterflex 10 days ago
          Empirically, it’s obviously necessary.
    • cardanome 10 days ago
      Time commitment is not really the limiting factor as to why people are out of shape anyway.

      HIIT is not a cheat code. Yes, technically it is just 1 minute of active exercise but oh boy will that minute feel like ages, especially if you are out of shape.

      It should intuitively make sense that that low intensity over a longer time and higher intensity over a shorter time would equal to roughly the same results (no exactly, they train slightly different things but let's keep it simple.)

      Whether you do HIIT or low intensity exercises, at the end of the day you still have to put in the work. There is no shortcut.

      People that are completely out of shape can do basically anything and it will give them great results. The hard part is building a habit of exercise.

    • urthor 10 days ago
      The concept is still worth knowing.

      Intersperse sprinting into your jogging is extremely important. Or other similar intensity lifts.

      • pbhjpbhj 10 days ago
        Fast sprints, fartlek [Swedish], in jogging was a thing 20+ years ago (Wikipedia says it was developed in 1930s). I got a knee injury and haven't jogged since, is it still a thing? Is this HIT a refinement of that?
  • airbreather 10 days ago
    There is various science around from multiple sources that suggest that HIIT High Intensity Interval Training or SHIT Super High Intensity Training puts the body in a different mode for some time afterwards.

    When the heart is stimulated to between 80 and 95% capacity (depending on source of information) this then prompts physiological changes that last long past the exercise event.

    CSIRO in Australia has been researching this for many years and is the premium (though still slightly woeful) scientific body in Australia.

    Not many real hills where I live, but there is one nearby and you often see people sprinting up it (sometimes backwards) and walking down, multiple times.

    One good plain language summary (not from CSIRO) is:

    "The “LifeSprints” study by Boucher in 2011 suggests that in the lower intensity steady state cardio trials, not enough levels of epinephrine (adrenaline) were present to stimulate fat breakdown in the muscle cells. During and after higher intensity exercise epinephrine and norepinephrine floats around in the system which stimulates “hormone sensitive lipase” to start breaking down fat in the fat cells. Therefore, the presence of epinephrine could be considered a major lipoliptic factor in fat breakdown (Trapp, Chisholm & Boutcher, 2007). During higher intensity exercise reaching maximal levels, not only does the body switch to carbohydrate as a main source of energy, a by-product of the anaerobic system (as seen in maximal intensities) is lactic acid. Lactic acid is said to be a blocker of epinephrine."

  • stefan_ 10 days ago
    Oh good, another of the weekly studies that finds having sedentary people do a light exercise regimen of any kind sees their fitness improve just as others doing light exercise.

    Can't wait for the meta study of "it doesn't really matter what you do".

  • Aldipower 10 days ago
    Ok, guys go ahead and do it this way. I stick with my marathon training plan, "which just works"™. Of course, there are also high-intensity workouts included, but the foundation is based on "easy runs" and sightseeing with the bike. There are just no short-cuts. I call the title of the post BS.
  • jononomo 10 days ago
    Back in 2011, I went through a phase in which I ran on the treadmill for 21 minutes several times a week. I would jog at 8-9 MPH for 2:15, then sprint all-out for 45 seconds at 10.5 or 11 MPH. The only other exercises I did were some light-weight squats and a handful of oddball machine exercises. I was also on a paleo diet.

    After I had been doing this for a few months (not more than 4 months) a friend of mine invited me to take part in a half-marathon. Prior to the half marathon, I only went on two long runs with my friend (over ten miles).

    When the big day came I finished the race in 99 minutes -- which is a 7:30/mile pace for the entire race. I was 35 years old at the time.

    I was astounded at how well I performed given my training regimen -- I ended up near the top of my age class!

  • curiousllama 10 days ago
    Having dabbled in a couple different exercise disciplines, I’d encourage very small updates to your priors from this study.

    Every bodybuilder knows that you have to push to failure and rest a lot between sets. The term for low-intensity or unrested lifting is “junk volume.”

    Every runner knows that 80% of your volume should be easy. It’s called “80/20 training.”

    Every CrossFit bro knows you need both intensity and volume - and maximizing that over time is what’s important.

    They all work, but in different ways + for different reasons.

    There’s lots of studies that try to break the mold. Usually, they’re limited by the impracticality of a large N, or perfect adherence, or exogenous factors, or avoiding hype. It’s a limitation of the field. It just means things will go slower. Don’t worry too much about any one study.

  • urthor 10 days ago
  • mathieuh 10 days ago
    How do they define fitness? It seems their definition is quite narrow.

    I cycle, and basically in the winter I do shorter rides more often to hit the same overall distance as I would in the summer. It's just not enjoyable for me dealing with awful road conditions and freezing hands and feet.

    E.g. in winter I'll do four or five 40 km rides per week, but in summer I do two or three 40 km rides and one 100+ km ride per week.

    It always takes me six weeks or a couple of months at the start of summer to build back up to doing 100+ km rides, even though I'm doing the same distance and spending similar amounts of time.

    • smcl 10 days ago
      I don't think this is saying 1 minute of high-intensity sprints is better than all other exercise, if you're doing multiple 40+ km bike rides per week you're probably not the intended audience for this type of exercise. However, I do think it is fair to use the word "fitness" as short-hand for what they were measuring because the below (from the "Results" in the Abstract linked) is a bit of a mouthful and doesn't neatly fit in the title:

      " Peak oxygen uptake increased after training by 19% in both groups (SIT: 32±7 to 38±8; MICT: 34±6 to 40±8ml/kg/min; p<0.001 for both). Insulin sensitivity index (CSI), determined by intravenous glucose tolerance tests performed before and 72 hours after training, increased similarly after SIT (4.9±2.5 to 7.5±4.7, p = 0.002) and MICT (5.0±3.3 to 6.7±5.0 x 10-4 min-1 [μU/mL]-1, p = 0.013) (p<0.05). Skeletal muscle mitochondrial content also increased similarly after SIT and MICT, as primarily reflected by the maximal activity of citrate synthase (CS; P<0.001). The corresponding changes in the control group were small for VO2peak (p = 0.99), CSI (p = 0.63) and CS (p = 0.97). "

    • rTX5CMRXIfFG 10 days ago
      From the abstract:

      > insulin sensitivity and other indices of cardiometabolic health

      The word “fitness” appears nowhere in the paper’s entire summary.

  • kilgnad 10 days ago
    I've done this for a decade. It's real. I exercise a couple minutes doing all out sprints 3-4x a week and it increased my VO2 max faster then running 5 miles everyday. I've tried both. The increase in performance is dramatic. Like you can bring yourself to way above average VO2 max performance doing HIIT on the daily.

    I want to emphasize though that one thing I noticed is that this is exclusively for VO2 max. I'm not sure if this type of exercise is good for the long term. It's good for increasing your performance.

  • wantsanagent 10 days ago
    Has anyone got an optimized home setup for this strategy? What equipment and/or monitors do you have and what specific exercises do you do? How to you incentivize your consistent adherence?
    • mokash 10 days ago
      i'd recommend a rowing machine. targets a lot of muscles, allows high/low intensity cardio, and is low impact to help reduce the probability of injury
  • Tade0 10 days ago
    I've been doing something like this lately, only accidentally.

    The distance between my apartment and daycare is 1300m and there are three road/street crossings on my way, so especially on one 240m stretch of wide pavement I can go as fast as possible without endangering my toddler. I average no less than 6km/h on this route.

    I'm as sedentary as they get and indeed I'm seeing some improvements. That being said this wasn't the only recent lifestyle change, so it might well not be a significant component.

  • alz 10 days ago
    It looks like they made people do things that require more short term oxygen uptake and as a result they adapted to be able to uptake more oxygen in the short term. I wouldn't so readily dismiss the myriad of other physical adaptations that result from long term, high volume, low intensity exercise, such as improved bone density, better fat metabolism, stronger heart muscles, better endurance and resilience, better mental health and cognition etc.
  • glomgril 10 days ago
    If you are out of shape, do one set of pushups once a day (however many feels comfortable even if you have to cheat a bit). Start small, even just a couple, and gradually increase the reps over time. You will be blown away by the results after even 2-3 months.

    Probably works best if you are scrawny to start with but I imagine any out of shape person would benefit.

    Given it takes less than 1min per day, everyone has time for something like this.

  • andy_ppp 10 days ago
    As I understand it the body has different energy systems- one that is aerobic and takes hours over months and years to train and anaerobic that all out short efforts can train. Everything in between these two is arguably time wasted. I think the title here is misleading and looking at another comment it’s not what the paper says, “it improved insulin sensitivity and other indices of cardio-metabolic health”.
    • xarope 10 days ago
      There is plenty of literature to show the body has 3 main energy systems (phosphagen, glycolytic - aka anaerobic, and mitochondrial respiration aka aerobic), and many activities are a combination of all these energy systems.

      Further, doing pure anaerobic activities without warmups (which are more aerobic in nature) would increase injury risk; whilst low intensity/aerobic oriented activities have been shown to improve general health and well being, which would also be important to maintain an athlete's ability to train over a longer period of time.

      So perhaps it's not as polar nor "time" wasting as you think as you think.

    • rTX5CMRXIfFG 10 days ago
      I’m sorry but this makes no sense:

      > the body has different energy systems- one that is aerobic and takes hours over months and years to train and anaerobic that all out short efforts can train. Everything in between these two is arguably time wasted.

      The body does indeed have aerobic and anaerobic energy systems but any chronic physiological adaptations to any exercise takes time.

      • andy_ppp 10 days ago
        So I'm getting this from Peter Attia, his suggested regimen in 45 mins 3-4 per week of zone 2 and one zone 5 all out Tabata style workout and 3-4 strength training sessions.

        Not 100% sure if he's right or not but he's probably more informed than either of us. When I talk about time I'm talking about total time in use of these systems - not the time it takes for them to get better which I actually know nothing about.

        • 000d 10 days ago
          What I think he means is that separating your workouts into zone 2 and 5 is "optimal" in terms of anaerobic contribution. At zone 2 your anaerobic contribution is low, while at zone 5 it is high. Its best to think of these energy systems as a sliding scale, and his model is based on the theory that zone 2 is the optimal window on this scale for improving metabolic health.

          This doesn't mean that zone 3 and 4 are useless. Most endurance athletes do most of their high intensity in these zones because the stress of zone 5 is not manageable over time.

    • marginalia_nu 10 days ago
      > Everything in between these two is arguably time wasted.

      This is if we're myopically focusing on cardiovascular and metabolic outcomes.

  • KVFinn 10 days ago
    The opposite extreme, slow zone-2 cardio, is important too. It takes forever, but the upside is you can burn through your Netflix queue while doing it.
  • MezzoDelCammin 10 days ago
    personally, I'd be cautious of using this article to build up an exercise routine.

    Yes, intervals / HIIT are really effective and they consume relatively little time. Being an egineer it's tempting to use this as a base for some sort of 80-20 heuristics and simply say "this is good enough" and cut the aerobics.

    But is it? It's definitely better than doing nothing. But if the goal is some sort of performance improvement (specially in endurance sports - cycling, running, etc.), 9 times out of 10 I'd go with what's today called "polarized training".

    The basic idea of polarized training is "yes, intervals are definitely useful to push the body further, but only after a buttload of cardio". The routine then looks something like for every one very low intensity, very long duration session a week, there's one or two shorter all-out interval sessions.

    The intervals alone would lead to a plateau pretty quickly...

    Happy to provide references in follow-ups, if anyone is interested.

    • balfirevic 9 days ago
      > But if the goal is some sort of performance improvement (specially in endurance sports - cycling, running, etc.)

      It probably isn't, for most non-athletes and people who don't have a sport hobby.

      > yes, intervals are definitely useful to push the body further, but only after a buttload of cardio

      I definitely won't be doing "a buttload of cardio", so we're back to square one - what is a good 80:20 heuristics that balances time investment, discomfort and results.

    • affgrff2 10 days ago
      Interestingly, the polarized training you describe is also know as the 80/20 rule that specifically recommend the opposite (80% low intensity + 20% high intensity) of what you mean by 80-20 (do just 20% to gain 80% of results).
      • MezzoDelCammin 10 days ago
        ah, misunderstanding. What I meant is the somewhat natural tendency to see the 80% gains in 20% effort and then say "80%, that's good enough".
  • notyourday 10 days ago
    That's just another out of context study jumped on by people who absolutely positively want to find a way to justify sitting on their ass, eating excessive amount of ultra processed carbohydrates and moving as little as possible

    Huberman currently is doing a series on fitness with Galpin. I highly recommend listening/watching it to get the context.


    TL;DR: there are different kinds of fitness and to be in a reasonable health over the long term one needs to have all of them.

    • brodouevencode 10 days ago
      Just came here to plug this - a lot of material, A LOT of material, and the latest one released today is nearly 5 hours. But if you are at all interested in this kind of stuff it's very much worth the listen.
  • deterministic 10 days ago
    I highly recommend reading “Body by Science”. It shows how you can improve your overall muscle strength spending just 15 min in the gym once a week. Perfect for people like me who hate going to the gym. It’s simple. It works. I am 50+ and way stronger now than I was before.
  • mkl95 10 days ago
    I went from virtually no exercise to moderate exercise for 15min, 4 to 6 times a week. Mostly 2 to 3 minute rounds on a heavy punching bag. I wouldn't call it life changing from a physical point of view, at least not yet. But the mental benefits were there from the first month.
  • happypants23 10 days ago
    People actually benefit from both low-intensity and high-intensity exercise. One is not a substitute for the other. Endurance athletes know this.

    Low-intensity exercise conditions aerobic energy pathways (mitochondrial respiration) in ways that high-intensity exercise cannot.

  • marmada 10 days ago
    Can someone confirm what intensity is high intensity?

    E.g, I have a rowing machine that leaves mildly out of breath and makes my heart beat quickly, is that HIIT? Or is HIIT more like stair climbers, which cause me to almost collapse after doing them for 12+ minutes.

    • finnh 10 days ago
      If you can do it for more than 1 minute, than it's not high intensity.

      Not to say it's not a good-great workout, but it's not the HI in HIIT.

      Also - hello fellow punishment lover! I rowed in high school & college & used to own an erg and am considering buying another one. They are so. fucking. time. efficient (HIIT evangelism be damned).

    • shlant 10 days ago
      from the study - "'all-out' cycle sprints (~500W)"
  • jvm___ 10 days ago
    My best running times were in 2017 when I did a 7 minute workout for 90 days in a row. I was doing the routine twice by the end of the 90 days.

    The 7 minute workout was a fad in 2012? that promised the same results as this study. Minimal time effort, maximum results.

  • bschwarz 10 days ago
    ...in sedentary men
  • robochat42 10 days ago
    Doesn't high intensity exercise have a greater risk of injury ? For instance, they did sprint intervals here, I think that I might need a 15 minute run just to warm up my knees enough to do the sprints (getting older sucks).
    • balfirevic 10 days ago
      > they did sprint intervals here

      Cycling sprints, on exercise bike.

  • psychphysic 10 days ago
    Research is important for research sake.

    But can anyone explain why these studies are like cat nip to the public and tabloids?

    "Any and All exercise is worthwhile (up to a limit)" and "unhealthy food bad for you"

    Over and over and over again...

    • oblio 10 days ago
      Because a huge percentage of the populations (yours truly included) lives unhealthy lifestyles and they want an easy way out or they have aspirational goals (think New Year's resolutions) they will never reach and do like being reminded of them occasionally.

      And tabloids frequently get to use cute/sexy pics for these articles, so more clicks.

    • HPsquared 10 days ago
      There is a big demand for column inches.
  • chewbacha 10 days ago
    Only 25 men were used? How can we possibly extrapolate that to others??
  • adave 10 days ago
    There are low intensity but high impact moves as level called compound moves that work as well. Focus on 10+mins in VO2 max on your tracker and go from there.
  • throwaway4good 10 days ago
    Is it not a bit of a scientific straw man? Most exercise classes, aerobics, CrossFit, whatever, contains bursts of high intensity exercise?
  • ck2 10 days ago
    Sure okay on paper.

    Now show me the average 5K race time for each group.

    The 3x 45minute group would destroy the 8 minute sprint group.

    It's all in how you define "fitness"

    • jononomo 10 days ago
      Why are you so confident? See my other comment.
      • ck2 10 days ago
        The way you trained was almost exactly the same as the 3x 45 minute group.

        What you call a 45 second sprint at the end is similar to what trained runners do after a run called strides. It has no similarity to the sprint training group.

        You did not say how many weeks you trained. It was roughly 20 miles per week which yes is enough to do a half-marathon in 1:40 for an average 35 year old man which is considered the "open" category (though races also do age-groups)

        Had you increased to 40 miles per week you could have done a marathon in around 3:25

        Running has been studied for so many decades by so many people that it's almost a science with very few surprises unless someone turns out to be exceptionally genetically gifted.

        • jononomo 10 days ago
          Thanks for the informative comment!
  • mateusfreira 10 days ago
    Devs next week: 0. git commit 1. git push 2. open an MR 3. powerlifting while the CI is running ....

    Business idea: powerlifting bars to homeoffices

  • nottorp 10 days ago
    The real question is how do you get people to exercise something, anything, daily. Not what exactly they should do.
  • mouzogu 10 days ago
    1 second of super high intensity exercise 3x a week improves fitness as much as 59x aerobics
  • mftb 10 days ago
    It's also a great way to get injured. Then you can't exercise at all.
    • aqme28 10 days ago
      Is it actually any more injury prone?
      • mftb 10 days ago
        It's a fair question. I didn't see any mention of injury in this study and I never see it discussed in these threads. I also admit my bias, I'm an older runner, and I've seen a lot of people struggling, who've unwittingly, been over-optimizing training and just over-training.
      • brodouevencode 10 days ago
        As with everything fitness, it depends.
  • amelius 10 days ago
    I have one question: why did it take humans so long to figure this out?
    • GuB-42 10 days ago
      I guess "exercising" is a relatively new thing in human history. Normally, calories are something you want to save, not something you want to lose. People worked out by doing actual work, training or playing.

      If you think about it, the idea sounds completely ridiculous. Doing a minute of painful of physical activity with no practical use because you are too busy not moving. If you go back in time with this idea people will probably ask you what crime you committed to deserve such punishment. For it to make sense, you need an unnatural combination of abundant food, sedentary work and little free time, which only recently became a thing for commoners.

  • rax0m 10 days ago
    What about bone strength though?
  • roxgib 10 days ago
    n=10. n=6 for the control group. I stopped reading at that point.
  • jrochkind1 10 days ago
    It says "Free PMC article", but I'm having trouble finding anywhere to click to see the whole article instead of just abstract and citations.

    Can anyone help me get it, whether that's me missing a place to click, or getting around paywall?

    • pfisherman 10 days ago
      Click on “full text links”. You could also click the doi link address.
  • bcd3169 10 days ago
    N = 27