The unique variety of workouts you’ll find in P90X3 are not just to keep you from getting bored. They are an integral part of the science. From an almost endless pool of possibilities, the various modalities chosen to become part of the Muscle Acceleration system were rigorously screened for not only individual effectiveness, but for how they integrate with each other and for how they progressively overload your system to force adaptation over the course of 90 days.