P90X Workout Program: Really the Best for Burning Fat, Building Muscles?

Muscle confusion fitness programs are hot, but are they better than plain-old weight lifting?

By + More

Have you heard of the latest fitness phenomenon that has folks working out like crazy six times a week? It's called P90X, and it's one of the top 5 fitness DVDs on Amazon.com. The program, which some users consider to be more like a newfound religion, employs lifting weights using a technique called muscle confusion. This involves switching-up resistance training exercises so your body doesn't become accustomed to the same repetitive movements every time you work out. If your body adapts too well to your workouts, the theory goes, it won't build muscle as efficiently as when it's faced with unpredictable movements. Hence, the confusion.

[Try This 10-Week Workout Routine]

Fitness trainers who teach muscle confusion techniques say that the ultimate goal is to avoid that muscle building plateau that most of us face when we've been lifting weights for a while. "The goal is to keep the body guessing," says John Romaniello, a New York-based trainer and creator of the Final Phase Fat Loss training system, a muscle confusion program that can be downloaded for purchase. "Once your muscles adapt, your body will become more proficient at a certain movement or type of exercise. You'll use less energy and thus see diminishing returns," he explains.

[Shape Up With a New Video Game Workout]

Fitness experts stress that muscle confusion isn't synonymous with cross training. You can't simply jog one day and swim the next—or alternate resistance training for the arms with training for the legs. "It's not about making random tweaks to your routine," Romaniello says. Rather, he adds, muscle confusion techniques strategically vary the rest periods between weight lifting sets, the number of repetitions, the amount of weight you lift and the speed of your repetitions.

[8 Strength Training Tips for Women]

Whether muscle confusion really works to overcome those muscle building plateaus remains unknown. That's because there aren't any reliable scientific studies comparing the method against traditional weight lifting. What is known is that in order for muscles to grow, they must be regularly challenged with an increased amount of resistance—and they must rest for a day or two between sessions to repair themselves and grow.

That said, Romaniello and other muscle confusion devotees claim they've seen far more success with this technique—in terms of body fat loss and muscle gain—than with other fitness programs. At best, you'll see faster and better results from your workouts; at worst, you'll keep from getting bored by mixing up your routine a bit. Since muscle confusion techniques are tough to learn on your own, you'll probably want to invest in a DVD set, downloadable guide, fitness class or personal trainer to learn what to do, recommends Skyler Meine, co-founder of IdealShape, a fitness company based in Lindon, Utah that uses muscle confusion in its boot camp-style classes. Here's a list of some top sellers:

1. P90X: This 90-day program includes yoga, martial arts and cardio interspersed with weight training to "keep the body guessing." It emphasizes flexibility as well as strength and requires you to work out six days a week. The 13 DVD set retails for $140, which doesn't include the cost of supplements that the program recommends to enhance muscle building.

2. Final Phase Fat Loss: Romaniello's program, which includes manuals and DVDs, retails for $137 and incorporates 16 workouts that rotate through four different training styles each week including dynamic and strength-based. Dynamic training combines movement with bodyweight exercises, such as squats and lunges, and develops large muscle groups, while strength-based training focuses on completing a certain number of heavier reps rather than specific sets. "It recruits different types of muscle fibers because it's heavier, forcing your body to become stronger," Romaniello says.

3. Turbulence Training Fat Loss: This is a home fitness system comprised of eBooks and downloadable manuals which you can buy individually based on your goals, or as a complete program. The basic Turbulence Training for Fat Loss package is $39.95; the complete program is $77.

Whether you employ muscle confusion in your program or not, it's important to keep pushing yourself, Meine says. "Challenging your body in new ways, involving more muscles in your workout, and giving a little more each time—that's how you maximize number of calories burned," he adds. Bottom line: "Your workouts should stay hard. Don't look forward to it getting easier!"

Chelsea Bush writes for AskFitnessCoach, a blog that promotes fitness and weight loss for "real" people.