Scientist busts myths about how humans burn calories

Because following that logic, exercise supposedly does not work if you want to lose weight. But if every study around aerobic exercise arrives at that conclusion, why aren't the majority of athletes overweight? Where are the fat runners?

Is this a survivor bias? (Fat people even with great aerobic capacity end up hurting their joints so they stop running)

Is it because the addition of exercise generates other kind of changes in the body, like less insulin resistance, and overall more signals in the body to burn fat rather than store it?

Do runners spontaneously change their diets once they get used to their new lifestyle? Maybe the food they used to eat, both in amount and in composition, makes them uncomfortable so they start making lasting changes?

Yes, it does look like running a static amount every time has diminishing results. But, overall, people who run tend to be less overweight. And a lot of overweight people who start doing exercise and stick to it, tend to lose the weight, or at least they lose fat and gain muscle.

The pandemic starts, I had surgery a month before the working from home mandates, I stopped smoking (5 cigarettes a day, we know they tend to suppress appetite, but it not like meth, there are plenty of fat smokers) and I quickly, say in two months, put on around 10 kg (90 to 100 kg+), and for the first time since I was an early teenager, I had a belly.

I was exercising less, not counting calories at all, I was not spending calories going outside (work, errands, nights out all got cancelled), and I was hungry all the time despite eating more than usual. All factors that can explain my weight gain.

This unfortunate situation goes on for one year more or less, then I started losing some weight by simply eating less and going out more, at least that was my explanation. But I noticed a visible change in body shape and composition after a two-week vacation in which my diet was McDonald's at nights and a huge breakfast in the morning with all calorie-dense food, basically.

Fast forward a few months, some improvement here and there, but I am still not at my pre-pandemic fitness level, still a bit fat, muscles not as visible as I like. I then go to NYC for a couple of weeks and my diet is McDonald's, ice cream and nothing of the healthy sort. Sure, humidity, heat, walking much more, they can all contribute to non-trivial increase in energy expenditure. But I come back looking like a million bucks, pre-pandemic fitness level if not better.

I keep in shape, then I get covid and I pretty quickly put some weight on (again...), say 5-10 pounds (sure, these swings are also water stored in glycogen, some of the weight quickly gained also goes away pretty quickly). I then go on a long-weekend vacation, walk much more than usual but no exercise (gym, running, combat sports), eat and drink more than usual, and, again, I observe a visible change in my body composition. I am leaner, I lost weight, I see (some) abs.

Someone could say, you are simply exercising more via walking and other non-exercise related energy expenditure, and MCDonald's two times a day can be at I have problems now accepting that our metabolism and our physiology is not a lot more malleable than I (and science) thought it was. I now start to believe that our "state of mind" (conscious or unconscious) can have a much bigger effect on our physiology, including metabolism, than expected according to "settled science". I am talking about our "mind" perceiving a new state of world (vacation for example) and very quickly adapting to the new perceived "stress" by changing my physiology, it could be different nutrient partitioning (decrease insulin resistance?) or simply higher metabolic rate. Or it could be the opposite, such as perceived "normal life" as stressful thus increasing, say, insulin resistance, and vacation as "relaxed mode", decreasing cortisol and insulin resistance etc. We all know we can "think" ourselves sick, but we "think" ourselves leaner?

Yep, my form is atrocious and inefficient due to bunions and Morton's toe which has evolved into hammer toe.

I'd argue that I burn calories more efficiently, however :)

Speakman thinks that limit is too low, noting that cyclists in the Tour de France in the 1980s and ’90s exceeded it. But they were injecting fat and glucose directly into their bloodstreams, a practice Pontzer thinks might have helped them bypass the physiological limits on converting food into energy."

Is this really true, that cyclists are injecting fat and glucose directly into their bloodstreams? I can't believe that. I have never heard that before.