In the simplest words possible, the last one standing is the winner of the battle. In order to be the last one standing, one must be able to sustain a level of physical activity in order to outlast his foe. Through rigorous exercise and training, one can condition one's self in order to be able to sustain his fighting level longer. Fatigue, not your enemy's blade can be the killer on a battlefield, because when fatigue is near, you can bet that blade is right behind it.