90X Workout X90 Workout - Version 1.0 Thousands of people every month hop online to search for the x90 workout or the 90x workout, when neither of these programs exist. I figured it was a good idea for me to post this, and steer those people in the right direction. The actual name of the workout they're all searching for is P90X, which is short for Power 90 Extreme. This program, created by fitness expert Tony Horton, is a response to the demand of his Power 90 graduates for a more advanced version of that well known workout program. The rest is history.