# Compound vs Fitbod: variety or progression

> Fitbod's algorithm builds a new workout each session from your equipment and modeled recovery. Compound repeats the same four workouts and adds weight.

**Source:** https://trycompound.cc/blog/compound-vs-fitbod/  
**Author:** Scott Shumaker, maker of Compound  
**Published:** 2026-09-12  
**Topic:** The app (app comparison, the app, progressive overload, exercise variation)

## In short

Compound or Fitbod comes down to whether you want a new workout generated each session or the same one getting heavier. Fitbod's algorithm scores 800+ exercises against your equipment and a modeled 0 to 100 percent recovery score per muscle group, trained on more than 400 million logged workouts. Compound runs one fixed four-day split and only adds weight, 5 lb on compound lifts or 2.5 lb on isolation work, once every set at the current target is hit on one identical weight, which needs the same exercise to come back around.

- Double progression adds one rep per session until a rep range tops out, then adds 5 lb on compound lifts or 2.5 lb on isolation work. On a five-to-eight range that is four clean sessions per plate jump, and it only works if the same exercise reappears to compare against.
- Fitbod scores more than 800 exercises against your equipment and a modeled 0 to 100 percent recovery score per muscle group, trained on over 400 million logged workouts.
- A trial that randomized exercise selection for 21 trained men every session for 8 weeks matched a fixed program on strength and most measures of hypertrophy, and improved training motivation.
- Fitbod's App Store listing showed $12.99 to $15.99 a month or $79.99 to $95.99 a year, checked 2026-08-22. Compound is $4.99 a month or $29.99 a year after a 14-day trial.

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Compound or Fitbod comes down to one difference: a workout generated fresh each
session, or the same workout getting heavier. Use Fitbod if your equipment or
location changes week to week, because it builds each session from what is in
front of you and a modeled recovery score. Use Compound if you want to add weight
to the same lifts, because its double progression needs an exercise to repeat
before there is a number to beat.

## What is Fitbod good at?

Fitbod removes the two decisions that keep people from training on their own:
what to do today, and whether today's equipment can do it. Its algorithm scores
all 800+ exercises in its library against the equipment you have told it you
have available, each session. Select only dumbbells and a barbell back squat will
not appear; add a cable machine to your gym profile and cable exercises become
eligible for the next session. The recommendations are trained on more than 400
million logged workouts, so a new exercise gets a starting weight seeded from
people with a similar training profile rather than a guess. For a hotel gym with
two dumbbells and a bench, or a commercial gym where the squat rack is never
free, that is a real problem solved. Nobody has to build a program, and nobody
has to stand in front of a rack deciding what to do first.

## Why does progressive overload need the same exercise to repeat?

Because there is no previous session to beat if the exercise changes. Compound's
double progression holds one weight until every set hits the top of the
exercise's rep range, at one identical weight, then adds the smallest plate jump
available and resets to the bottom of the range: 5 lb on a barbell compound like
a squat or bench press, 2.5 lb on isolation work like a curl or a lateral raise.
On a five-to-eight rep range that is four clean sessions per plate jump, one rep
added at a time, and it only works because the number the app is comparing you
to is the number from the last time you loaded that exact lift. Swap the squat
for a leg press and the comparison is gone. The new exercise starts over: a
fresh weight estimate, a fresh rep target, nothing to climb from. Continually
increasing the demand on a muscle, in load or in reps, is what a resistance
training program needs to keep producing adaptation rather than just maintaining
it, which is the whole basis for progression schemes in the first place. Progress
stops being a number you can point to and becomes a feeling, and a feeling is
much easier to be wrong about.

## What does the research actually say about exercise variation?

It says variation buys something real, but narrower than most people assume. A
12-week trial of 49 people tested four combinations of varying the exercise and
varying the training intensity.
The group that varied the exercise while holding intensity constant grew every
head of the quadriceps measured and posted the largest strength gains of the
four groups; the two groups that kept the exercise fixed each missed growth in
one or two of the three quadriceps heads. A separate 8-week trial randomized the
exercise selection of 21 trained men every session and compared it to a fixed
program. Strength gains and most measures of muscle thickness came out
statistically identical between the two, with one exception: one of the three
quadriceps regions measured grew significantly only in the fixed group. The
randomized group did report a significant improvement in training motivation,
while the fixed group did not. Neither study supports muscle confusion, the
popular idea that a muscle stops responding to a movement it has adapted to
and needs to be surprised to keep growing. Variation earned its keep through
regional muscle recruitment and through motivation, not through preventing some
adaptive plateau that a stable exercise would otherwise cause.

## What can't an algorithm know?

It cannot know anything you did not log. Fitbod's recovery model scores each
muscle group from 0 to 100 percent based on your recent training history and
favors exercises for muscles that have not been heavily trained in the last 48
to 72 hours. That is a real estimate built from real data, and it is a
genuinely useful one. It does not know that you slept four hours, that your
lower back is stiff from the drive, or that the squat rack at your gym is
occupied every night at 6 p.m. To be fair, neither does a fixed program. The
difference is that a fixed program never pretends to: the plan is the plan, and
you are the one deciding whether today is a day to push it or back off. An
algorithm that outputs a specific weight and rep count for you implies a certainty
about your readiness that a rep count and a rest timer cannot actually measure.

## How do the two apps differ, decision by decision?

The two apps disagree on almost every design decision underneath the workout.

| Decision | Fitbod | Compound |
|---|---|---|
| Who picks the exercise | An algorithm, scoring 800+ exercises against your equipment, goal, and modeled recovery each session | The plan. Four fixed days, pull, push, legs, auxiliary, set before you open the app |
| Does the exercise repeat | Sometimes. Recovery scoring and exercise rotation mean a given lift is not guaranteed to reappear next session | Always. The same slot returns every time that day comes around, for example Barbell Back Squat every Legs day |
| How weight is chosen | An estimated one-rep max from your logged sets, or a starting weight seeded from aggregate user data when you have no history on that exercise | Held at the last working weight. It rises only when every set at the current rep target is hit at one identical weight |
| What happens after a missed set | Folds into the algorithm's ongoing recovery and strength estimate for future sessions | Nothing changes. The same target repeats next time, with no deload and no reset |
| Where the data lives | An account, synced to Fitbod's servers | A JSON file in Application Support, on the device, with no account and no network |
| What happens with no history on a lift | Falls back to population-level estimates from other users with a similar profile | The lift opens at the bottom of its rep range and climbs from whatever weight you enter |

## Who should use Fitbod instead?

Anyone who travels for work, trains across more than one gym, or cannot predict
what equipment will be free when they get there. Fitbod's whole design center is
adapting to what is in front of you, and that is a genuinely hard problem a
fixed plan does not solve at all: Compound has no answer for an occupied squat
rack. Fitbod is also the better choice for anyone who finds doing the same four
workouts genuinely intolerable and would quit a fixed program rather than repeat
it. Adherence beats optimality. A program you actually do beats a better program
you abandon in six weeks, and if variety is what keeps someone training, that is
not a small thing to trade for a slightly cleaner progression curve.

## What does Compound do about it?

Compound accepts that the same four sessions, forever, is boring by design, and
that boredom is a real reason people quit. It does not try to solve that with
variety. It solves the decision instead: every set logged against the current
target either moves the number for next time or it does not, and nobody has to
decide what that number should be. The bet is that a bar which reliably gets
heavier is worth more than a workout that reliably looks different, and that the
app should spend its cleverness on getting that one number right rather than on
picking a new exercise for you.

## Common questions

### Does Fitbod track my progress on the same exercise?

Yes, when that exercise comes back around. Fitbod estimates a one-rep max from your logged sets and updates it as you improve, but its exercise selection changes session to session based on equipment and modeled recovery, so a given lift is not guaranteed to reappear the way it does in a fixed program. When it selects a lift you have not done recently, it starts from a population estimate rather than your own last session.

### Is exercise variation bad for muscle growth?

No. Varying exercise selection while holding other variables constant has been shown to grow more regions of a muscle than a fixed exercise does, and one trial found no difference in strength between a randomized and a fixed program. What the research does not support is muscle confusion, the popular idea that a muscle needs to be surprised to keep adapting.

### Does Fitbod require an account?

Yes. Fitbod personalizes every workout from your logged training history and a modeled recovery score, which is stored against an account you create with email or a sign-in provider. Compound stores training history in a file on the device and never asks for an account.

### How much does Fitbod cost?

Fitbod's App Store listing showed $12.99 to $15.99 a month or $79.99 to $95.99 a year with a 7-day free trial, checked on 2026-08-22. Pricing varies by region and changes over time, so check the current listing before subscribing.

### Who should use Fitbod instead of Compound?

Anyone whose equipment changes week to week, such as frequent travelers or people training across more than one gym, and anyone who finds a fixed set of four workouts genuinely hard to stick with. Adherence beats a marginally better progression curve.


## Sources

- [Fitbod: How Fitbod Generates Your Personalized Workouts](https://fitbod.me/blog/fitbod-algorithm/)
- [Fitbod: Gym & Fitness Planner, App Store listing](https://apps.apple.com/us/app/fitbod-gym-fitness-planner/id1041517543)
- [Fonseca et al. (2014): Changes in Exercises Are More Effective Than in Loading Schemes to Improve Muscle Strength](https://pubmed.ncbi.nlm.nih.gov/24832974/)
- [Baz-Valle et al. (2019): The Effects of Exercise Variation in Muscle Thickness, Maximal Strength and Motivation in Resistance Trained Men](https://pubmed.ncbi.nlm.nih.gov/31881066/)
- [American College of Sports Medicine (2009) Position Stand: Progression Models in Resistance Training for Healthy Adults](https://pubmed.ncbi.nlm.nih.gov/19204579/)

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*Scott Shumaker, maker of Compound. Builds Compound, an iPhone and Apple Watch app that runs one lifting program and does the bookkeeping. Trains on the pull, push, legs and auxiliary split, and wrote the progression engine described here.*

*Compound: A workout app with exactly one workout in it. Four days, automatic double progression, warm-up and mobility built in. No account, no cloud. https://trycompound.cc*