The workouts are varied, incorporating resistance training, cardio, plyometrics, abs work, martial arts, and yoga.
P90X is something of a "cult classic" workout program, and it's got a hard-core reputation—after all, the X stands for "extreme." Created by Tony Horton, the challenging workouts are done for one hour a day, six days a week, for 90 days. The workouts are varied, incorporating resistance training, cardio, plyometrics, abs work, martial arts, and yoga.