P90X is an intense exercise program that helps people build muscle in 90 days. P90X promises to accelerate fitness through a concept called “muscle confusion,” which involves changing workouts regularly and preventing the body from fully adapting. This encourages muscle growth and fat burning.
P90X workouts range from 60 to 90 minutes. They feature fast, challenging exercises that are not suitable for beginners. The program is sold as a set of 12 DVDs and includes cardio, yoga, core exercises and workouts that target specific body parts such as the shoulders and back. As of 2014, Beachbody sells P90X through its website. Some gyms offer classes led by certified P90X instructors.