For athletes, the most important part is recovery. They only spend 3-4 hours per day "working", the rest is spent traveling, preparing, eating and sleeping. The key is good recovery, to be fully energized and focused at "working" sessions, for maximum quality (and productivity). It also helps if you have a coach, a manager and a private chef. And I think the same also applies if you want to be a successful entrepreneur: Quality over quantity. You have to love it though, because it's often hard work, and painful.