When we work out rigorously, our bodies limit our ability to expend energy(nytimes.com)
nytimes.com
When we work out rigorously, our bodies limit our ability to expend energy
https://www.nytimes.com/2019/06/12/well/move/pushing-the-limits-of-human-endurance.html
77 comments
If this is something that bodybuilders have known for ages, I have to readjust my ideas about body building.
This paper (https://advances.sciencemag.org/content/5/6/eaaw0341) is about a 140 day event were runners, on average, run a marathon a day. It also states
”The mechanisms underlying this metabolic compensation are unclear but likely include reduction in nonexercise activity and reduction of physiological activity in other organ systems. Changes in running cost could also contribute, but evidence for training-induced improvement in running efficiency is mixed and the effect, when present, is generally modest, ~3% savings in energy per kilometer”
So, it doesn’t seem more efficient running explains the lower energy expenditure. Instead, it’s just that, as the days went on, they dropped dead in their bed earlier every day, and their bodies postponed doing long-term maintenance (my interpretation)
This paper (https://advances.sciencemag.org/content/5/6/eaaw0341) is about a 140 day event were runners, on average, run a marathon a day. It also states
”The mechanisms underlying this metabolic compensation are unclear but likely include reduction in nonexercise activity and reduction of physiological activity in other organ systems. Changes in running cost could also contribute, but evidence for training-induced improvement in running efficiency is mixed and the effect, when present, is generally modest, ~3% savings in energy per kilometer”
So, it doesn’t seem more efficient running explains the lower energy expenditure. Instead, it’s just that, as the days went on, they dropped dead in their bed earlier every day, and their bodies postponed doing long-term maintenance (my interpretation)
Yeah reduction in NEAT is fairly common in prolonged caloric deficits.
https://en.wikipedia.org/wiki/Thermogenesis
https://www.strongerbyscience.com/metabolic-adaptation/
https://en.wikipedia.org/wiki/Thermogenesis
https://www.strongerbyscience.com/metabolic-adaptation/
[deleted]
Yep. Runners usually do sprints to break through plateaus.
you can add training load in lots of ways. most evidence suggests a mix of mostly low intensity with some very high intensity is optimum no matter how much total running you do. but the first order thing is just to get as much load as you can handle.
I am just the occasional runner, but have been thinking about adding weights to make them more intense, however, I am very hesitant for fear of doing long term damage to my joints?
It's unclear from your comment whether you mean weights while running or separate weight training. Adding weights while running tends to lead to injury and isn't a good idea. Adding more running, adding more intense running (sprinting, intervals, or fartleks), or adding non-running weight training (squats, deadlifts) can all improve your running and are good ideas.
As someone who runs a lot with a pack that typically weighs forty pounds, I highly recommend that you not do this. FWIW, I don't believe I'm damaging my joints by what I do, but I spent many years hiking with a pack and then many years running without a pack before I started running with a pack.
It can, however, be done: https://github.com/ctm/Bataan-Memorial-Death-March
It can, however, be done: https://github.com/ctm/Bataan-Memorial-Death-March
I wouldn't recommend using weights for any kind of distance. If you want to up the intensity, it's generally considered safer to do 400m/800m sprints, hill sprints, sled/prowler, etc.
Why do you want to get better?
At some point, exercise has diminishing short and long term benefits and becomes actively harmful.
This isn’t true for everyone, but I stopped running years ago because I could see it would have long term detrimental effects on me. I still exercise, but I think I have a good understanding of where I want to be and just to maintain at that level.
At some point, exercise has diminishing short and long term benefits and becomes actively harmful.
This isn’t true for everyone, but I stopped running years ago because I could see it would have long term detrimental effects on me. I still exercise, but I think I have a good understanding of where I want to be and just to maintain at that level.
Source for this? Middle-aged runners look like they're in great shape. Evidence suggests long-distance running, if done correctly, has no adverse effects on the body. We've literally evolved for it
”Middle-aged runners look like they're in great shape”
That’s not a valid argument. It could be survivor bias, with those still running (and not dead, bound to a wheelchair at 30, etc) looking great.
Even if, taking that into account, runners look better than non-runners, there, a priori, is no guarantee they wouldn’t have looked even better without it.
That’s not a valid argument. It could be survivor bias, with those still running (and not dead, bound to a wheelchair at 30, etc) looking great.
Even if, taking that into account, runners look better than non-runners, there, a priori, is no guarantee they wouldn’t have looked even better without it.
Definitely not an anti-exercise site:
https://www.active.com/health/articles/why-too-much-running-...
Not to mention shin splints, torn Achilles, etc.
Of course there are diminishing returns if you are running for the purpose of living a longer, healthier life.
As far what we “evolved for”. There is no evolutionary benefit of living past the age where you can pass on your genes and endure the next generation can do the same. There is no evolutionary pressure for a people to live pass that age.
Evolution would never favor a trait that would allow a population to live be 100 instead of 60.
https://www.active.com/health/articles/why-too-much-running-...
Not to mention shin splints, torn Achilles, etc.
Of course there are diminishing returns if you are running for the purpose of living a longer, healthier life.
As far what we “evolved for”. There is no evolutionary benefit of living past the age where you can pass on your genes and endure the next generation can do the same. There is no evolutionary pressure for a people to live pass that age.
Evolution would never favor a trait that would allow a population to live be 100 instead of 60.
Evolution is more complicated than you realize.
Kin selection is the term you need to read up on for our current explanation on why we live so far beyond reproductive age.
https://en.wikipedia.org/wiki/Kin_selection
Kin selection is the term you need to read up on for our current explanation on why we live so far beyond reproductive age.
https://en.wikipedia.org/wiki/Kin_selection
> Evolution would never favor a trait that would allow a population to live be 100 instead of 60.
It would. Grandparents care for grand children. In fact, they seem to have an uncanny ability to inculcate them with the desire for having more children, of their own. Hmmmm ;)
It would. Grandparents care for grand children. In fact, they seem to have an uncanny ability to inculcate them with the desire for having more children, of their own. Hmmmm ;)
I am not saying “old people are useless”. I’m saying that there wouldn’t be evolutionary pressure to allow people to survive pass 60. It’s believed that we evolved to have stamina for long distance running to tire out our prey. The elders wouldn’t be the hunters.
Point being: Caring for grandchildren makes them more likely to survive and pass on your genes. Asking them every Christmas dinner when they’re gonna give you great grandchildren, too, apparently.
In the hunter gatherer society where our stamina would mean we eat. They would have the female stay with the children....
Passing on useful knowledge, for example, concerning rare but catastrophic events could be an evolutionary reason for people to live far past child bearing age.
Would you need to pass that knowledge on for two generations instead of one?
I read recently about an Aboriginal tribe in Australia that managed to weather a once in 50 years level drought because there was one man in the tribe who was old enough to remember where they got water the last time there was a drought that bad.
Naturally, knowledge transfer won’t be complete or perfect, so it seems plausible that there’s an evolutionary benefit to much younger generations to having some really, really old people around.
I mean, I’m not trying to argue for exactly what happens, mostly just contesting the idea that there’s no evolutionary reason for people to live way past child-rearing.
Naturally, knowledge transfer won’t be complete or perfect, so it seems plausible that there’s an evolutionary benefit to much younger generations to having some really, really old people around.
I mean, I’m not trying to argue for exactly what happens, mostly just contesting the idea that there’s no evolutionary reason for people to live way past child-rearing.
Your suspicions are correct; that would be a bad idea.
What are your goals?
What are your goals?
Why not just add sprinting?
There's a trend of funding & publishing research that yields completely obvious results and when you point it out you always get downvoted to hell on HN, don't know why.
It's because occasionally "obvious" claims are wrong, and having research that confirms them gives us a firmer foundation of knowledge. The article mentions that this is one of the first studies to quantify energy expenditure in this way, which would mean it's bringing the "obvious" claims into the edifice of scientific knowledge. Non-novel research results are an important (and underrated/underincentivized) part of science.
The article may be leaning too heavily on claims that the results are surprising, but that has little to do with the research.
The article may be leaning too heavily on claims that the results are surprising, but that has little to do with the research.
I do wish we could just buckle down and figure out diet and exercise related health knowledge. So many diet and exercise related studies just have too small sample sizes and are too narrow. This makes sense because it’s expensive and time consuming to track a lot of people’s diet and exercise routines to get rigorous results. I think, however, we should just bite the bullet and pay $10 billion (or however much) to precisely track several thousand people’s diet, exercise, sleep, etc and figure this out. Basically pay people as a full time job to eat and do what you tell them (ethically of course. They aren’t slaves. We just need better data than sample sizes of twenty people trying to track their own health with self reported diaries).
Most of what we need to know, for most of the population, we already know.
Even if the effort you suggested were to be done, the noise would continue to distract in exactly the same way.
I've worked as a tech exec, and I've worked as a personal trainer, and I've competed... we have the knowledge. We know how people can be healthy, we know how people can live long lives, and we know how people can have bodies that are a benefit to their lifetimes, not a burden.
I remember a study, it graphed a demographic of people across a scale from "healthy" to "unhealthy". What they found was that people were heavily represented on either end of the scale, but to a significant degree, not at all in between.
So, the choice is... people's (barring economics, to some degree, I'll concede -- though, being poor in other countries isn't the health catastrophe that it can be in some first world countries).
Even if the effort you suggested were to be done, the noise would continue to distract in exactly the same way.
I've worked as a tech exec, and I've worked as a personal trainer, and I've competed... we have the knowledge. We know how people can be healthy, we know how people can live long lives, and we know how people can have bodies that are a benefit to their lifetimes, not a burden.
I remember a study, it graphed a demographic of people across a scale from "healthy" to "unhealthy". What they found was that people were heavily represented on either end of the scale, but to a significant degree, not at all in between.
So, the choice is... people's (barring economics, to some degree, I'll concede -- though, being poor in other countries isn't the health catastrophe that it can be in some first world countries).
Yup, there's a lot of information that can seem to point in contradictory directions, but you get some very, very clear signal out of it in a couple of important directions.
People still seem pretty resistant to simple interventions like this though. I think a big part of it is that most people have an incredibly powerful status quo bias, and get extremely uneasy with diverging from the norm of behavior they see around them (even if those norms are of generally far worse health than they're targeting).
I've spent the last decade incrementally understanding more about nutrition and optimizing my diet, and I've reached the point where the divergence between mine and my friends' diets has become pretty insane. Not coincidentally, now that we're starting to enter the period where age catches up with our bodies, I'm by far the healthiest, by both appearance and symptoms. I've had friends ask me what I do, but it's far enough outside the norm that they assume it's impossible or that I have iron willpower (spoiler: I really don't. If you eat healthy, your tastes shift towards healthy food).
This is a general problem with people; in the narrow case, it could be solved by changing their environment (ie blanketing the country with PSAs with simple messages, like we did for smoking). It would do infinitely more good to somehow grant people the intellectual confidence (or indeed, capability) to avoid blunt heuristics like the so-called "wisdom" of crowds, but I have no earthly idea how one would do that.
People still seem pretty resistant to simple interventions like this though. I think a big part of it is that most people have an incredibly powerful status quo bias, and get extremely uneasy with diverging from the norm of behavior they see around them (even if those norms are of generally far worse health than they're targeting).
I've spent the last decade incrementally understanding more about nutrition and optimizing my diet, and I've reached the point where the divergence between mine and my friends' diets has become pretty insane. Not coincidentally, now that we're starting to enter the period where age catches up with our bodies, I'm by far the healthiest, by both appearance and symptoms. I've had friends ask me what I do, but it's far enough outside the norm that they assume it's impossible or that I have iron willpower (spoiler: I really don't. If you eat healthy, your tastes shift towards healthy food).
This is a general problem with people; in the narrow case, it could be solved by changing their environment (ie blanketing the country with PSAs with simple messages, like we did for smoking). It would do infinitely more good to somehow grant people the intellectual confidence (or indeed, capability) to avoid blunt heuristics like the so-called "wisdom" of crowds, but I have no earthly idea how one would do that.
Sometimes you may believe some things to be obvious, but they must be confirmed through the scientific method for further progress in that field to continue. It's like writing Hello World in a new language before doing more advanced things.
But this is worse. The article doesn't focus on switching around your routine at all! It's not even about effectiveness of training, it's about total energy output.
It's a HN comment that repeats a trope and then people on HN complain that it's obvious.
It's a HN comment that repeats a trope and then people on HN complain that it's obvious.
Does anybody have the sane reaction as me?
I often feel much less hungry if I do some physical exertion than when I spend day more or less still.
I often feel much less hungry if I do some physical exertion than when I spend day more or less still.
I do. My personal feeling is that I use food for energy when not working out. When I work out I get energized and won't need to fill up with food as much to feel energized.
Could be primal and hormonal. A situation where you need to run isn't usually the same situation you should stop and eat.
> When I work out I get energized
After I work out I want to nap.
After I work out I want to nap.
I think so, but I never really measured the actual amounts I eat, and what, in both cases. It also heavily depends on what you're doing when sitting still: using your brain actively for work for instance is going to require quite some energy in comparison with just sitting still and relaxing. AFAIK the brain's main energy source is sugar so my (completely unverified - it's hard these days to find the truth amongst the insane amount of dietary bs out there) assumption is that physical exertion needs / can use different metabolic pathways not requiring instant sugar intake.
Something related happens to me as well, during light physical exertion: even when I get hungry, I can just keep on going and after like 30 minutes I don't feel the hunger anymore, and can keep on going for a couple of hours more. That just doesn't work for me when programming/debugging: then I keep on being hungry and after a while just cannot think properly anymore (could be placebo/confirmation bias, unsure.)
Something related happens to me as well, during light physical exertion: even when I get hungry, I can just keep on going and after like 30 minutes I don't feel the hunger anymore, and can keep on going for a couple of hours more. That just doesn't work for me when programming/debugging: then I keep on being hungry and after a while just cannot think properly anymore (could be placebo/confirmation bias, unsure.)
> using your brain actively for work for instance is going to require quite some energy in comparison with just sitting still and relaxing
Does it? I've always wondered if this was the case but according to this post it doesn't vary significantly: https://biology.stackexchange.com/questions/839/how-does-the...
Does it? I've always wondered if this was the case but according to this post it doesn't vary significantly: https://biology.stackexchange.com/questions/839/how-does-the...
Now that's suprising, thanks.
There's a lot of metabolic and information-processing housekeeping that needs to be done regardless of what we are thinking about. Even the sleeping brain is quite active.
The difficulty of hard mental problems is not necessarily related to the physical work needed, even when we recognize that information processing is a physical process - for example, figuring out when to leave for a lunch appointment is not necessarily less physically demanding than solving a differential equation.
The difficulty of hard mental problems is not necessarily related to the physical work needed, even when we recognize that information processing is a physical process - for example, figuring out when to leave for a lunch appointment is not necessarily less physically demanding than solving a differential equation.
According to my Google research, "brain activity" is not a valid excuse for eating more sweet snacks.
Brain can work also on ketones. This is exactly what is the point of keto-diet. It resists as much as possible to switching in this mode, I have to admit.
Definitely for some time (up to 2-3 hours) after the workout. If I'm trying to lose weight I'll deliberately work out before lunch or dinner so I don't eat as much.
Exact opposite here. I get much hungrier on days that I work out. I basically need to eat an extra meal to not feel ravenous. Not great for weight loss unfortunately.
You and GP are saying slightly different, not mutually-exclusive things, that matches my experience:
For a good hour or two after the exercise, I'm barely hungry at all. Three or more hours afterwards, and I'll be far hungrier than I would normally have been at that time.
For a good hour or two after the exercise, I'm barely hungry at all. Three or more hours afterwards, and I'll be far hungrier than I would normally have been at that time.
After weight training I am always hungry like crazy. But try to stick to healthier snacks so it won't counter your weight loss as much :)
Depends on the exercise. Cardio can suppress appetite for a time, resistance training not so much.
In my experience cardio only suppresses appetite for the duration of the cardio. So even running two hours a day (a lot more than most runners, including myself, do), there's still ~14 hours of day to cram calories in my face.
Depends on intensity. Vomiting after marathons and triathlons isn't uncommon, and intensity that's slightly lower than that can still induce nausea which can last awhile. Reactions to all sorts of training are largely individual I think.
> Vomiting after marathons and triathlons isn't uncommon
Those are long distance, race intensity efforts. Most workouts aren't going to be race pace and most runners for fitness aren't running marathon distances, esp. not for every workout. In my experience, the nausea quickly subsides once my heart rate drops below 190.
> Reactions to all sorts of training are largely individual I think.
Totally agree. I was talking about my personal experience (anecdotal).
Those are long distance, race intensity efforts. Most workouts aren't going to be race pace and most runners for fitness aren't running marathon distances, esp. not for every workout. In my experience, the nausea quickly subsides once my heart rate drops below 190.
> Reactions to all sorts of training are largely individual I think.
Totally agree. I was talking about my personal experience (anecdotal).
I read that happens when you have just started exercising/working out, or when you do it irregularly. Something about sudden stress switching the body into survival/fight or flight mode.
When the exercise is regular, it becomes routine
When the exercise is regular, it becomes routine
Nope, nothing makes me as ravenous as excercise. I’m also not trying to lose weight, so that might be a difference.
No, complete opposite. I lose weight (muscle glycogen probably) when I miss workouts, because my appetite decreases significantly.
I feel that running suppresses my appetite somewhat. I have wondered if the bouncing of my gut produces feelings of being full, or even slightly irritates it.
There's a sweet spot of physical activity which optimizes energy expenditure:appetite. Too little or too much and your appetite is higher than your expenditure.
https://www.ncbi.nlm.nih.gov/pubmed/22855277?dopt=AbstractPl...
https://www.ncbi.nlm.nih.gov/pubmed/22855277?dopt=AbstractPl...
Has that sweet spot been quantified as a multiplier of resting metabolic rate? Would love to experiment around with that number.
The article seems to say that the 60-min cardio group had been closer to that sweet spot, but it's not very concrete about that assumption.
The article seems to say that the 60-min cardio group had been closer to that sweet spot, but it's not very concrete about that assumption.
No, but that's completely unrelated to the article, isn't it?
This study has a sample size of three. Worth taking with a large pinch of salt.
The validity of “doubly-labeled water” results is dubious at best in an organism with so many pathways to feed the citric acid cycle. Specifically I’m referring to fat adaptation and protein catabolism. Also, how does 600*(3.5-2.5)=6200/3.5?
Is this not simply explained by the body becoming more econonmical at repeating the same action over time?
After 6 weeks of daily running the body will adapt to be more effcient at running, so won't need so much energy to perform the same activity.
After 6 weeks of daily running the body will adapt to be more effcient at running, so won't need so much energy to perform the same activity.
That would make sense in an average person, but if you're an elite who is physically capable of back to back marathons, you don't have that much more running economy to gain -- after thousands of lifetime miles, your running economy is already near optimal.
I don't think so. For instance, pro cyclist have been doing nothing but cycling training for years and years. And still, this effect shows up a few weeks into a Grand Tour.
As they mention at the end of the article, from gorging research (eating as much as possible to gain weight) it is also known that the body can't ingest more calories than about 2.5x times the normal daily energy output. So it's more likely that that is the limiting factor -- in the first weeks you have some reserves to burn, but when those are gone your body doesn't burn more energy than it can take in.
As they mention at the end of the article, from gorging research (eating as much as possible to gain weight) it is also known that the body can't ingest more calories than about 2.5x times the normal daily energy output. So it's more likely that that is the limiting factor -- in the first weeks you have some reserves to burn, but when those are gone your body doesn't burn more energy than it can take in.
I wonder if this phenomenon can serve to explain burnout syndrome?
This is also true wrt to fasting. I consumed less than 400 calories a day and after 3 weeks my weight plateaued.
Paywall. Can anybody give a tl;dr?
Short article that includes a bunch of information from this new paper: https://advances.sciencemag.org/content/5/6/eaaw0341
I read that paper shortly after it came back and sent this info to a friend:
I've read the entire paper and I don't buy their conclusion. Basically, I think they're saying that at > 2.5x BMR, you simply are burning more calories than you can process. I think that a more likely culprit is body damage, which although vague, is definitely something different. Here's a telling portion from their own article:
> An alimentary limit of ~2.5× BMR is consistent with the SusMS versus activity duration curve, which flattens out below ~3× BMR (Fig. 1B), but raises directions for further research. First, in at least two studies (Tour de France cyclists and elite Nordic skiers; table S1), subjects maintained metabolic scopes of 3× to 5× BMR without substantial weight loss.
The weasel word "substantial" is present and I guess one could argue that perhaps they had small amounts of weight loss that would add up, but I don't think that's what they're really saying. Between Marshall Ulrich's experience (where he set the age record and then was kind of fucked up for about a year, IIRC) to my own experience where the harder I run the more it beats me up, even in short distances where I can and do eat (and drink!) more post-race and hence gain weight, my guess is that they're being fooled by the correlation between the increase in damage that's done the harder one runs and the corresponding increase in calories needed. As such, they come up with a useful rule of thumb, but their explanation of "alimentary limit" (which is in the title "Extreme events reveal an alimentary limit on sustained maximal human energy expenditure") is just not the case.
Although I don't think it would be easy to find subjects to do such a test, my guess is if you could find a low-impact protocol for raising BMR higher than 2.5x and you were to do it long enough, with "good" nutrition that it would be fairly easy to surpass their magic number. However, that's trickier than it sounds. Riding a stationary bicycle, for example, probably is lower impact than the "running" that was done, however, there are reasons to believe that while shorter distances are lower impact, longer distances may not be, because a bicyclist has less freedom to alter which joints/tendons/muscles he/she stresses and hence you hit the weak-link-in-the-chain syndrome, even though it may take a while to get there. Also, riding a stationary bicycle is boring as hell.
Really, if you take out the "substantial" weasel word from the paragraph I quoted, I think it's pretty damning. However, I think they had a hypothesis and wanted to justify it. On one hand the authors have much greater scientific chops than I do. On the other hand, I'm a fairly analytical person and I have a lot of experience with endurance events, although not much multi-day stuff and my longest multi-day event, the Tahoe Two Hundred, was marred by a (minor, but cumulatively very annoying) toe/foot injury that I sustained on the second day.
Oh, and back to that quoted paragraph: I think the participants in Tour de France and elite Nordic skiers) are much more likely to be significantly more fit (both from a cardiovascular perspective as well as tougher skins, ligaments, and muscles) than the RAUSA runners and that would be in keeping with my hypothesis.
I read that paper shortly after it came back and sent this info to a friend:
I've read the entire paper and I don't buy their conclusion. Basically, I think they're saying that at > 2.5x BMR, you simply are burning more calories than you can process. I think that a more likely culprit is body damage, which although vague, is definitely something different. Here's a telling portion from their own article:
> An alimentary limit of ~2.5× BMR is consistent with the SusMS versus activity duration curve, which flattens out below ~3× BMR (Fig. 1B), but raises directions for further research. First, in at least two studies (Tour de France cyclists and elite Nordic skiers; table S1), subjects maintained metabolic scopes of 3× to 5× BMR without substantial weight loss.
The weasel word "substantial" is present and I guess one could argue that perhaps they had small amounts of weight loss that would add up, but I don't think that's what they're really saying. Between Marshall Ulrich's experience (where he set the age record and then was kind of fucked up for about a year, IIRC) to my own experience where the harder I run the more it beats me up, even in short distances where I can and do eat (and drink!) more post-race and hence gain weight, my guess is that they're being fooled by the correlation between the increase in damage that's done the harder one runs and the corresponding increase in calories needed. As such, they come up with a useful rule of thumb, but their explanation of "alimentary limit" (which is in the title "Extreme events reveal an alimentary limit on sustained maximal human energy expenditure") is just not the case.
Although I don't think it would be easy to find subjects to do such a test, my guess is if you could find a low-impact protocol for raising BMR higher than 2.5x and you were to do it long enough, with "good" nutrition that it would be fairly easy to surpass their magic number. However, that's trickier than it sounds. Riding a stationary bicycle, for example, probably is lower impact than the "running" that was done, however, there are reasons to believe that while shorter distances are lower impact, longer distances may not be, because a bicyclist has less freedom to alter which joints/tendons/muscles he/she stresses and hence you hit the weak-link-in-the-chain syndrome, even though it may take a while to get there. Also, riding a stationary bicycle is boring as hell.
Really, if you take out the "substantial" weasel word from the paragraph I quoted, I think it's pretty damning. However, I think they had a hypothesis and wanted to justify it. On one hand the authors have much greater scientific chops than I do. On the other hand, I'm a fairly analytical person and I have a lot of experience with endurance events, although not much multi-day stuff and my longest multi-day event, the Tahoe Two Hundred, was marred by a (minor, but cumulatively very annoying) toe/foot injury that I sustained on the second day.
Oh, and back to that quoted paragraph: I think the participants in Tour de France and elite Nordic skiers) are much more likely to be significantly more fit (both from a cardiovascular perspective as well as tougher skins, ligaments, and muscles) than the RAUSA runners and that would be in keeping with my hypothesis.
Just Google for it from an incognito session to get the full article. I quoted the gist of the research in the other post but here goes:
Because there's a limit to how much a human body can eat a day, body also regulates how many calories the body can burn in a day.
So you can do one day where you burn more than 6000kcal but any more days and 6k is the rough limit, even if you run a full marathon.
Body adapts, but it also doesn't let you burn too many calories over consecutive days.
No needs to do anything fancy (to read it), just hit the refresh icon and cancel it _almost_ immediately. Click-20ms-click.
Excellent! that worked first pop!
I'd be loading the paywall JS first before the content if I was running the site.
I'd be loading the paywall JS first before the content if I was running the site.
TL;DR pay for the journalist’s work if you want to read it
Although pro sportspeople can have huge energy outputs in single matches, those that go to extremes (like marathons on consecutive days for weeks, or riding a Grand Tour race, or being pregnant -- they looked at a wide range of things) won't exceed 2.5 times their normal "rest" energy output per day, after a few weeks. Even if their pace doesn't go down much, so they become more efficient after those weeks.
There is also research from gorging for weight gain that concludes that the body can't take in more than 2.5x the daily "rest" energy use in calories, so the two seem linked.
There is also research from gorging for weight gain that concludes that the body can't take in more than 2.5x the daily "rest" energy use in calories, so the two seem linked.
Nothing counterintuitive about these results. Anyone who has ever exercised knows that he has to switch things up if he intends to keep breaking the plateau either for strength or weight loss.
Our body is incredibly good at conserving energy which is why we feel less tired running 5kms daily after a while.
Only interesting point is the barrier on how quickly we can reach this efficiency with the limitation of how much fuel we can consume.
Our body is incredibly good at conserving energy which is why we feel less tired running 5kms daily after a while.
Only interesting point is the barrier on how quickly we can reach this efficiency with the limitation of how much fuel we can consume.
clarify: you don’t have to switch things up, but you do need to continually increase training load. switching things up may help psychologically for some but not all.
I don’t know about counterintuitive but the article says they don’t know where the savings are coming from. If we have the capacity to be more efficient why not always be more efficient? Presumably there’s some trade off.
Being more efficient during higher energy demands doesn't necessarily optimize you for the same conditions with lower demands. It would be interesting to re-calculate energy expenditure at rest for the over-exercised grouped.
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I don't think running 5km daily reaches the 2.5x of daily rest energy use hard limit that they found across this wide range of athletes. The article isn't about that effect.
Not sure why they call the findings surprising. Body builders have known that since before Schwarzenegger.
Body adapts and then you have to change the routine.
For long distance runners HIIT or just short, intense workout would be the obvious answer to up the metabolism again.