Keep yourself fit to stay alive. Planet Nomads is a life and death struggle. Your hunger, thirst and stamina levels are not just numbers on the screen. When they fall to critical levels you're going to feel that. Without stamina, you won't be able to move. You may suffer from negative conditions induced by weather conditions or dangerous enviroment around you. Bleeding drains your health and stamina. Radiation sickness wears you down on all fronts. All of this is bad - there's no place for the weak in the wild.