Building smart fitness guidance with Fitbod

How Fitbod for iOS demystified the gym for both amateur weightlifters and hardened gym rats alike.

One year ago today, we distributed an early prototype of Fitbod to a small group of strength-training hobbyists at our local gym in San Francisco. The ambition behind Fitbod — to eliminate the guesswork in planning gym workouts— resonated with anyone who’s tangled with the bent steel and daunting contraptions found at the gym.

Before Fitbod, we struggled with the mental gymnastics of blending past workouts, hundreds of exercises and unique gym idiosyncrasies into a concrete workout plan.

Which muscles did I work out last time? What exercises can I do with this equipment?

One year later, Fitbod users collectively perform over 250,000 exercises per week from personalized workout plans created by Fitbod’s automated workout builder. In this story, we describe the underlying principles behind Fitbod’s fitness approach and transformation of raw workout data into smart fitness guidance.

Bridging the gap between activity tracking and active behavior

Today’s leading health & fitness products allow users to track and view physical activity, promising to educate and motivate individuals to lead healthier lives. A gap exists, however, between activity tracking and active behavior, with these products failing to offer concrete, personalized guidance for developing physical fitness.

Recent research from the Journal of the American Medical Association suggests that the knowledge gained from self-tracking fails to end in self-help:

“The gap between recording information and changing behavior is substantial, and while these devices are increasing in popularity, little evidence suggests that they are bridging that gap.”” — JAMA. 2015;313(5):459–460

Consumer fitness technology today is like Google Maps without directions. With self-tracking, we have data-rich maps of people’s physical activity, but fail to help them navigate towards real results.

Fitbod bridges the gap with smart, individualized guidance for strength-training. When you’re ready to workout, Fitbod builds a exercise routine–in real time–that efficiently targets fresh muscles with the most suitable exercises. Pair this superpower with strength training best practices and Fitbod improves upon today’s primitive activity trackers.

To build anyone’s most effective workout, Fitbod examines muscle recovery state, exercise history and a variety of personal preferences.

Built on fitness first principles

Fitbod puts strength-training best practices in anyone’s hands by grounding the design of workout routines in fitness first principles. The following principles not only guide how Fitbod assembles exercises into a workout plan, but also how we design individual features.

Balance — Individual muscles benefit when working in concert with the entire muscular system. Overworking some muscles while underworking others can negatively impact results.

Variation — Mixing up muscles, exercises, sets, reps or weight between workouts promotes strength gains. Sets, reps & weight recommendations are based on a non-linear periodization resistance technique, which alters the intensity/volume relationship for every workout. Prilepin’s formula is used to calculate a recommended volume and intensity for any exercise.

Individualization — Results are best achieved by tailoring the workout program to your unique body, experience, environment and goals. For example, Fitbod leverages time-tested formulas to understand each individual’s level. A canonical example is the One-Repetition Maximum: a measurement of an individual’s maximum amount of force generated in one maximal contraction. One rep max is considered an upper limit and used to recommend weight for an exercise (as a percentage of the 1RM). We calculate One-Rep Max using a modified Brzycki formula.

Three surfaces representing our fitness first principles. Today (left) displays a single recommended workout that balances targeted muscles over time. Available Equipment (middle) allows you to see recommended exercises using your available equipment. The final surface (right) displays an exercise screen with a suggested sets/reps/weight scheme.

What’s ahead for Fitbod?

Today, users log over 1 million exercises per month from personalized workout plans created by Fitbod’s automated workout builder. Over 2 thousand beta testers and thousands of weekly active users love the simplicity of a single workout that adapts as they improve. Many have ditched their fixed workout plans, “7-minute workouts”, and notebooks.

Fitbod’s addressable market includes the 80 million Americans who utilize resistance and cardio equipment at the gym or home. Gym memberships in the USA have grown by over 22% since 2009.

We know that a huge number of under-active people could use fitbod to live healthier lives, with nearly 80% of the US population failing to meet the Physical Activity Guidelines set by the CDC. Fitbod is the solution for this market, standing at the intersection of the growing health-tech and personal training industries.

In Fitbod first year, we reached thousands of weightlifters with the tools to work out more productively. In year two, we’ll promote strength-training as an accessible fitness option to a much wider audience, inspiring millions of under-active to lead stronger lives.


Download on the iOS App Store

Fitbod builds custom-fit strength-training workouts and leads the emerging category of smart fitness guidance. Today, Ftbod users log over 250,000 exercises per week from personalized workout plans created by Ftbod’s automated workout builder. More about Fitbod »


Appendix: Product Walkthrough

©2017 Fitbod Inc.