When we work out rigorously, our bodies limit our ability to expend energy
nytimes.com
nytimes.com
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.
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.
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.
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 ;)
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.
Kin selection is the term you need to read up on for our current explanation on why we live so far beyond reproductive age.
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.
It can, however, be done: https://github.com/ctm/Bataan-Memorial-Death-March
What are your goals?
The article may be leaning too heavily on claims that the results are surprising, but that has little to do with the research.
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).
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.
It's a HN comment that repeats a trope and then people on HN complain that it's obvious.
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)
I often feel much less hungry if I do some physical exertion than when I spend day more or less still.
After I work out I want to nap.
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.)
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...
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.
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).
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.
When the exercise is regular, it becomes routine
https://www.ncbi.nlm.nih.gov/pubmed/22855277?dopt=AbstractPl...
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.
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.
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'd be loading the paywall JS first before the content if I was running the site.
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.
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.
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.