As a 90 day fitness program, the p90x program has withstood the test of time. Thousands of students swear by the p90x workout program as a key to their success in weight loss. Others have utilized the p90x program to build strength and become toned like never before. The p90x program is revolutionary, because it works off of a concept known as "muscle confusion." The concept of "muscle confusion" works as follows. "Muscle confusion" makes muscles grow, because it exposes them to varying conditions in each workout. Every workout is different from the last, which enables a person to build muscle fast. The p90x program also helps a person build his or her endurance. After a couple weeks of doing the p90x workout sessions, a person will notice how much his or her endurance has improved. Runnin