Beachbody LLC is an American multinational corporation that uses multi-level marketing to sell fitness, weight loss, and muscle building home-exercise DVD's. The company's best-known product is Tony Horton's P90X, whose TV ads have become some of the most frequently run infomercials in the United States. P90X is a 90 day workout regimen developed by Tony Horton that claims it can significantly improve fitness in three months through intense physical training. P90X's advertising emphasizes muscle confusion, a method of cross-training and periodization achieved through switching the order of exercises and incorporating new and varied movements. Muscle confusion supposedly prevents the body from adapting to exercises over time, resulting in continual improvement without plateaus. Insanity is a workout regimen similar to P90X in that it claims to improve fitness in 60 days through strenuous stamina training. Developed by Shaun T., Insanity's advertising emphasizes max interval training, a method of exercising during which one works out strenuously for 3-4 minutes and then rests or cools down for approximately 30 seconds before starting the whole process over again. This is
Contributions by Ashershow1, Memphisto, and Tharskjold.