Ah OK, say when you are on dev branch. Usually, BI introduces the new commands in https://community.bistudio.com/wiki/Category:Scripting_Commands_Arma_3
but nothing on stamina here!
I hope, but i'm sure not, BI will add fatigue and stamina as a difficulty parameter... one day!
And AI, already able to dead shot after 1km run and badly hurt?
Problem is BI is fond of realism for players, in regard to poor playability. That's probably a reason why, people would disable this parameters before their current release!
A training simulator for armies can't be a wide public game.