[PleasureBot]

There's been metabolic studies that show that this isn't true. Comparisons of total caloric usage of completely sedentary people and people who have high exercise load are indistinguishable. There is a large difference among individuals, but not correlated to exercise levels. Sedentary people who start training hard will have a spike in caloric usage for a few months, but their body adapts and calorie burn returns to the same level that it was when they were sedentary. This was new research, so there wasn't an explanation for it. The authors hypothesized that it could be that the body reduces caloric spend on other things, like stress responses, when it is adapted to high exercise levels/ They did note that some extremely elite athletes can temporarily increase their caloric burn (think Michael Phelps eating 10k calories per at some points when training for the Olympics) but its not something most people can achieve or sustain.

[soared]

Absolute nonsense. The claim is that if I produce 2.5watts per kg in body weight for 2 hours, I’m not going to burn any extra calories? So when I “bonk” and exhaust glycogen stores due to underfueling that’s actually not true?

[BobaFloutist]

I think that the claim is that what you're experiencing absolutely does happen, and your body responds by cutting corners on your baseline when you're sleeping or sitting around on the couch to avoid you starving to death (because it doesn't know that you can trivially increase your food intake if needs must).