Your algorithmic strength coach
Fitbod was founded in San Francisco in 2015 by Allen Chen, a former fintech VP, and designer Jesse Venticinque. Long before the generative AI wave, Fitbod applied machine learning to a stubborn problem: most people don't know what to do in the gym. The app generates a fully customized workout for every session based on your goals, experience level, available equipment, and — crucially — which muscle groups are fresh versus fatigued.
How the engine works
Fitbod models your recovery: after you log a session, it tracks the strain placed on each muscle group and steers subsequent workouts toward what's recovered, balancing training volume the way a good coach would. It supports gym, home, and travel contexts by adapting exercises to whatever equipment you have, tracks strength progression over time, and integrates with Apple Health and wearables. The app has surpassed 15 million downloads, 120 million logged workouts, and holds a 4.8-star rating from over 250,000 reviews — with a strong following among intermediate and advanced lifters.
Business
Fitbod is a subscription product with a free trial and has been largely capital-efficient, raising only a few million dollars in outside funding — a profitable contrast to venture-subsidized fitness apps.