No more plateaus. The core idea behind the P90X workout is called "muscle confusion." By doing a different type of workout every day you'll keep your muscles guessing, which means you'll keep them working hard.
2. Well-rounded workouts. Drawing from weight lifting, interval training, yoga, plyometrics, and martial arts, among other things, you'll work your body from every angle thereby increasing your power, strength, balance, and athletic ability.
3. Less risk of injury. Injuries often happen when you repeat the same motion over and over again, as in running. P90X has you changing up your routine so often that it reduces your risk of repetitive use injuries. Also, by working your muscles in different ways, you increase their resilience.
4. It's a challenge. "If it's easy, it's not working," is our trainer's motto. Is this workout for everyone? No. A lot of people are afraid to work hard. But if you're willing to take the risk, you're going to get results.
5. Mental toughness. Forcing yourself to try so many new things can be difficult, but once you find yourself doing something you never thought you could (pull-ups, anyone?), you realize that you're capable of a lot more than you thought.
6. All day calorie burning. Running may burn a lot of calories while you do it, but lifting weights and doing interval training will have you burning calories around the clock.