Staying in the Game - Part 2: Stamina

Stamina to my mind is something that professional athletes aspire to, especially those of the marathon and ultra-marathon persuasion. Come to think of it, anyone doing ultra-anything, probably has the have the stamina of a lion in mating season. Yeah, they go at it for days at a time - and without food!
Mating lions in the Chobe (c) Linzé BrandonSo where does it leave the writer?
Should we start getting fit to write for hours and hours at a time? Writing is an intellectual exercise and hours a...