How to increase stamina of human body?

Work at It, Exercise: People love easy answers (which do not exist) for many things (exception: look up “exercise in a pill” research); marketers routinely use this to sell bogus stuff. Military boot camp all about building endurance (plus team spirit & compliance with orders). Second, eat as healthy as you can, most evidence: natural fats, moderate protein, very low sugar, no proc. Carbs. Study: attia, taubes, lustig.