Isn't a warm-up necessary ?
A warm-up is necessary before sports activities where you are going to carry out high force movements that can produce injury. The risk for injury comes from the excess force not from exertion. In Concept 10 10 you work with force at a very low level. Also, as you fatigue, you literally become too weak to produce force enough to injure yourself. In Concept 10 10 the warm-up is built into the exercise.