[Gene_Parmesan]

It's worth noting that chess grandmasters can burn up to 6000 calories per day while competing in tournaments. It's an absolutely exhausting endeavor, and I imagine sheer endurance can play a huge role.

So yes, performance does fall off with age, though not as intensely as something like hockey.

[mattnewton]

Is that true? I thought that the difference between deep thinking energy expenditure and rest expenditure of the brain was not a huge % of the rest energy expenditure. I couldn’t find any source to the 6000 calorie figure, and this article seems to support that the chess player’s calorie deficit was likely due to skipping meals and stress https://www.livescience.com/burn-calories-brain.html

[pishpash]

The brain is an organ like any other and gets fatigued more easily with age.