It is part of why people argue that Chess is a sport.
When grandmasters battle it out for hours in classic chess, thinking ahead of so many branches of moves that I would find unfathomable, they do burn through a lot of energy.
For what is quite a sedentary career choice, I rarely see overweight grandmasters. Though that is probably more correlation of other facts than causation...
It’s probably also the case that being physically fit and healthy helps one think more clearly. Carlsen notably spends a lot of time on physical health in addition to prep.
When grandmasters battle it out for hours in classic chess, thinking ahead of so many branches of moves that I would find unfathomable, they do burn through a lot of energy.
For what is quite a sedentary career choice, I rarely see overweight grandmasters. Though that is probably more correlation of other facts than causation...