From our own experience we can say that physical activity is exactly what is missing the body and brain to be active.
As someone with Habra already wrote somewhere — mental energy is drawn from the physical. If the body heal, then dumalka is not working properly.
I used to think that sports is weaning time. And so on what is missing, and now exercise every day — all kick. However, only a half-hour of running a day increased the ability to work for at least two hours (fewer sleep and rest) + performance, if not increased, then became constant.
So I advise everyone: 2-3 times a week minimum, but you can often to run, play tennis, badminton or whatever