The Paradox of Exercise

heybales

It is interesting how the major metabolically active organs that account for the majority of the BMR in a body - vary between races and people in locales that have been there ages.

Several studies like this. And several studies I've seen reference this difference and account for it.
https://www.nature.com/articles/ejcn201122

Haven't read this topic's article if they even dug that deep to see if that is a difference.

But also that learned to move less angle. When food is scarce - nice ability to not be wasting it on useless movements.

AnnPT77

Speaking only for myself, though it's academically interesting, I fail to see relevance to my n = 1.

If I exercise beyond my current capability**, or fail to fuel my exercise adequately****, I'll get fatigued.

If I get fatigued, it will reduce my calorie expenditure throughout the day, in ways subtle to major.

I might get takeout instead of cooking at home, spending maybe 50 fewer calories on food prep. I may watch TV longer, rather than doing some optional home chores, same kind of caloric issue. I may buy some new t-shirts online, instead of walking around the mall looking at things to buy, or order groceries for pickup rather than wandering through a big-box grocery. I may fidget less (research shows differences between fidgeters and non-fidgeters potentially as much as low hundreds of calories daily). I may go to bed early, sleep being about the lowest-MET activity I could do, lower than that inert TV-watching, even.

So, fatigue is counter-productive.

At my n = 1, experience tells me I can optimize my TDEE by paying attention to daily life activity (NEAT), eating at a reasonable (not excessive) calorie deficit when I want to reduce my weight, and including exercise that's energizing rather than exhausting.

I don't see what difference this research makes to that n = 1.

** Via too-high intensity, insufficient recovery, or excessive duration. Some of those might be worth doing sometimes for reasons of fitness or fun, but with the recognition that doing it regularly can have unhelpful impacts on TDEE, overall life balance, etc.
**** I.e., try to lose weight at a rate that's silly-fast given my current size, health, etc.

heybales

yirara wrote: »

Took a while to find it back: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3405064/
this is what I read earlier today. There's more data there, some statistical analysis (didn't check that one), and also more questions that I have

This was interesting.
So they used DLW for getting a good TDEE measurement - but for BMR they calculated. Why didn't they measure!
True, based on some better specifics than a Harris or Mifflin BMR calc, but still based on mass population BMR equations.

"Physical activity level (PAL) was calculated as TEE/estimated BMR for each subject following previous studies [13]–[16]. To estimate BMR for Hadza subjects, we entered each subject’s body mass and height into age-specific prediction equations developed in a large sample (n = 10,552) from a geographically broad set of populations that includes populations in sub-Saharan Africa [27]."

And this is where the smaller organ size can slip through the cracks.

I recall one study of tribal background africans where even accounting for LBM being equal, the fact those organs was smaller though muscle was greater % of the LBM, the BMR was lower overall. Since most know the muscles by themselves don't burn that much extra as far as BMR.
So for them the standard BMR calc's was bad failure.

I can picture the opposite of what many families may do with their kids in some countries (well, not right now probably) - "why don't you go outside and play! get out of the house and off the computer/phone/tv"
Whereas in long-time culture of meals being more difficult to come by - "why don't you kids stop playing and come sit down and help prepare food for meal."

Just a picture that comes to mind, not based on any hard data except pictures of meal time and almost everyone helping prepare food.

sofrances

After a while, I have concluded y'all must be right. My weight loss has been faster than my calorie deficit (before exercise) would suggest, so either the maintenance calorie calculation is way off for me, or exercise must account for it. I have been doing the same exercise schedule for a while, so if there was some sort of adaption period my body must have adapted by now.

Still, its odd that scientists have come to a conclusion that seems to contradict my experience in a way which is difficult to explain. I mean, usually in an argument between me and a scientific expert I would expect me to be the one who is mistaken, but I can't find an obvious way that I could be in this situation.

NorthCascades

sofrances wrote: »

Has anyone read the article The Exercise Paradox?

It details a study of the Hadza people, who have a very active hunter-gatherer lifestyle (18000+ steps), but were found to use an average of 2400 calories. The researchers hypothesised that this means that, long term, exercise doesn't so much increase energy expenditure as change what they body spends the energy on. This may be why its so good for you - because it diverts energy away from harmful things like inflammatory processes etc.

I take this to mean that, long term, once your body has got used to higher level of exercise, you might not actually be able to eat back your exercise calories.

What do people think? Does this accord with your experiences of eating exercise calories etc.?

Were those calories measured using a metabolic ward, or roughly estimated?

If this is true, after years of running and training, it would mean that running a marathon doesn't burn any calories. How is that possible?

I have almost 6,000 miles on my current bike. I did a loop last night and burned about 1,150 kCal as measured by a power meter - which could be off by as much as 2.5% in either direction. So I'd say no this doesn't accord with my experience at all.

janejellyroll

sofrances wrote: »

After a while, I have concluded y'all must be right. My weight loss has been faster than my calorie deficit (before exercise) would suggest, so either the maintenance calorie calculation is way off for me, or exercise must account for it. I have been doing the same exercise schedule for a while, so if there was some sort of adaption period my body must have adapted by now.

Still, its odd that scientists have come to a conclusion that seems to contradict my experience in a way which is difficult to explain. I mean, usually in an argument between me and a scientific expert I would expect me to be the one who is mistaken, but I can't find an obvious way that I could be in this situation.

If a scientist is arguing that our bodies can perform activity without using energy, they're going to need excellent data to back up that assertion. They don't get the benefit of being assumed right just because they're an "expert." Everyone needs data to back their claims. The more exceptional the claim, the more documented it needs to be.

What has been presented so far is very far from conclusive.

AnnPT77

sofrances wrote: »

After a while, I have concluded y'all must be right. My weight loss has been faster than my calorie deficit (before exercise) would suggest, so either the maintenance calorie calculation is way off for me, or exercise must account for it. I have been doing the same exercise schedule for a while, so if there was some sort of adaption period my body must have adapted by now.

Still, its odd that scientists have come to a conclusion that seems to contradict my experience in a way which is difficult to explain. I mean, usually in an argument between me and a scientific expert I would expect me to be the one who is mistaken, but I can't find an obvious way that I could be in this situation.

Ummm . . . can I suggest that it's perhaps that you're misunderstanding what the scientist might be trying to say in this case? (That's not a criticism, this stuff is freakin' complicated!) I'm not a scientist, but I do have a theory - heh - about how to reconcile your experience with the science, without either of you being mistaken.

Science recognizes that individuals vary, and not always for reasons that are identifiable based on current knowledge (known unknowns, maybe even unknown unknowns).

On top of that, they vary for known reasons that are pretty much useless for large populations of people who just want to lose weight in a practical way. (heybales' post up there a few on this thread, about the influence of organ size, is an example).

On top of that, they vary for reasons that are quite well-understood, and potentially more usable, but for which most people lack the relevant data. (An example is muscularity. All other things equal, a person with substantially more muscle mass will burn slightly more calories than a similar-weight/height/age/activity person who has much less muscle mass. Some calorie estimators can use this information to refine (not perfect) their estimates, but most regular people don't have a good estimate of muscle mass (the BIA devices one stands on, or holds, are not very accurate)).

On top of theat, humans' daily life activity levels are extremely variable, because they exist on a continuum. The "calculators" usually ask us to pick from a list of 4-10 activity levels. Real humans don't behave in chunks like that - it's that continuum, really. Individuals can fall kind of between or beyond the 4-10 levels, more or less.

There are lots of other factors that matter a little: Fidgetiness (or its lack), possibly dietary composition (tiny effect), hormone-level effects (example: untreated hypothyroidism), more.

What any calorie "calculator" is doing, in effect, is asking you for a very small number of inputs, then spitting out an average calorie-needs value for the statistically typical person with those same characteristics. It's the best guess to use as a starting point, because it's at least (in effect) a large group average, and in a realm where the variation between individuals (the standard deviation, in statistical terms) is reasonably small.

But it's still a statistical estimate. It will be close for most people (because most people are typical, by definition, right? ), further off (high or low) for a few, and quite far off for a very rare few . . . because that's the nature of statistical estimates.

A little background, that only covers part of this:

https://examine.com/nutrition/does-metabolism-vary-between-two-people/

I'm not saying any of the above is the actual, true reason for your observations. As you say, it could be the exercise estimates. As others say, it could be the food estimates. Or you could simply be non-typical, possibly for non-identifiable reasons.

I don't think you're a special case that would confound your imagined scientist, fun though that may be.

And if you are scientist-confounding, I am, too. My calorie needs, based on almost 5 years of careful logging data, are 25-30% above what MFP (and my fitness tracker**) estimate for me. (** A solid, mainstream brand, and a model that many others here report estimates their needs quite accurately.)

I don't know why, specifically (I have some ideas ). But I'm pretty sure I don't live in some strange place outside of Science. :drinker:

sofrances

Good points @AnnPT77. I guess the way to work it out would be to vary the exercise and see if it makes a difference. Although I'm not sure I want to make myself an experimental subject like that.