P90 (2003)

P90 is Tony Horton's original 90-day home fitness program that laid the foundation for the acclaimed P90X series. Designed for beginners and intermediate fitness enthusiasts, the program uses progressive resistance training, cardio conditioning, flexibility, and core exercises to build strength, improve endurance, and promote weight loss. Organized into multiple phases that gradually increase in difficulty, P90 helps participants develop fitness safely while preparing them for more advanced training programs.