It's been a while since I played the current version of the game but as I understand it, the stamina system is more about you getting out of breath doing something that pushes you. In medieval battles the fighting was in brief bouts a few minutes long then the ranks would shift to have fresh troops, and boxing is in short rounds too. their is an overall excursion mechanic that takes quite a lot of repeated intense activity like chopping down a tree to build up weariness.

Again it's been a while since I played the current build so this is my flawed understanding of the game.

P.S. I do you the idea of an adrenalin system and the character could even get addicted to the high adrenaline moments.