The evidence behind the numbers

Full Coverage tells you how much of each muscle a workout trains. That is a claim about training science, so here is the work it rests on - including the paper that limits what we can honestly say.

The unit: sets per muscle

Training volume is counted in working sets per muscle. A set of bench press counts as a full set of chest and a fraction of a set of triceps, because the triceps assist rather than drive the movement.

One workout takes every muscle to 2-3 sets depending on your training goal - that is what 100% means, and it does not change with how often you train. Training more often multiplies it: at 2-3 workouts a week that is 4-9 sets per muscle. 11 fractional sets is the most one session can usefully deliver to a single muscle.

How a percentage becomes a dose

Every movement in the catalog carries a per-muscle activation percentage, and you can see all of them. Those percentages do NOT translate one-for-one into dose. For counting volume they are banded into three tiers:

Counts as	Role	Activation
1.0	Prime mover	70-100%
0.5	Strong assister	40-65%
0.25	Minor contributor	15-35%

The banding is deliberate, and the reason is the paper below: the precision needed to dose off a five-point difference in an activation estimate does not exist. The 1.0 and 0.5 tiers come from the published method. The 0.25 tier is ours - our vectors distinguish a real minor contributor from noise, and rounding those to zero would under-count real work.

Barbell Bench Press

3 × 6-10

Chest 100% → 3 sets Prime mover
Triceps 50% → 1.5 sets Strong assister
Front delts 40% → 1.5 sets Strong assister

One movement, worked through. The percentages are the catalog’s; the set counts are what the engine actually budgets with. This figure is generated from the live catalog - if a number in it changes, this changes with it.

How much each goal asks for

The per-workout dose is the one place a goal changes how MUCH you train rather than how you train, and it is not a separate constant: it is the goal’s own prescription, so “100% of a muscle” and “one exercise done as prescribed” are the same sentence. What IS ours rather than the papers’ is which band each goal aims at - the research gives a dose-response curve with diminishing returns, and that choice places each goal on it. Both numbers are shown here so they can be argued with.

Muscle mass 3 / workout 3x a week = 9 sets
Strength 3 / workout 3x a week = 9 sets
Lose weight 3 / workout 3x a week = 9 sets
General health 2 / workout 2x a week = 4 sets

What one workout gives a muscle at each goal, and what that comes to over a week at the frequency each goal calls for. A new account starts below the full dose and climbs over its first month - untrained lifters respond to less, and opening someone’s first week at a full hypertrophy dose is how people get too sore to come back.

What the model rests on

The source of the fractional method. Compared three ways of counting an assisting set across 67 studies and 2,058 participants, and found counting it as half a set predicted real-world gains best - concluding that telling direct and indirect work apart is essential.

Pelland JC, Remmert JF, Robinson ZP, Hinson SR, Zourdos MC (2025). The Resistance Training Dose Response: Meta-Regressions Exploring the Effects of Weekly Volume and Frequency on Muscle Hypertrophy and Strength Gains. Sports Medicine. 10.1007/s40279-025-02344-w
Why the unit is WEEKLY sets. Established the dose-response relationship between weekly set volume per muscle and muscle growth, and reported that even very low volumes produce substantial gains - which is why the app has a floor rather than an all-or-nothing target.

Schoenfeld BJ, Ogborn D, Krieger JW (2017). Dose-response relationship between weekly resistance training volume and increases in muscle mass: a systematic review and meta-analysis. Journal of Sports Sciences. 10.1080/02640414.2016.1210197
Why one workout a week is called maintaining rather than wasted. A review of the minimum dose needed to preserve what training has already built: strength and muscle size were maintained for up to 32 weeks on as little as one session a week and one set per exercise in younger adults, provided the load stayed heavy. Older adults needed about twice that. It is the source for the lowest of our weekly bands.

Spiering BA, Mujika I, Sharp MA, Foulis SA (2021). Maintaining Physical Performance: The Minimal Dose of Exercise Needed to Preserve Endurance and Strength Over Time. Journal of Strength and Conditioning Research. 10.1519/JSC.0000000000003964
Why we argue for full body on schedule resilience rather than on frequency. A meta-analysis of training frequency found no meaningful difference in muscle growth between training a muscle once, twice or three times a week once total weekly sets were matched. Distribution is not the lever; weekly volume is. So the honest case for full-body training is that it protects your weekly volume when a day goes missing - not that hitting a muscle more often is inherently better.

Schoenfeld BJ, Grgic J, Krieger J (2019). How many times per week should a muscle be trained to maximize muscle hypertrophy? A systematic review and meta-analysis of studies examining the effects of resistance training frequency. Journal of Sports Sciences. 10.1080/02640414.2018.1555906
Why cutting is not prescribed less work. A review of resistance training during caloric restriction. It is explicit that higher volume is NOT proven better for sparing lean mass while dieting - and equally explicit that programmes which REDUCED volume preserved less of it than those that held or raised it. So the fat-loss goal is given the same frequency as muscle mass, rather than fewer sessions.

Roth C, Schoenfeld BJ, Behringer M (2022). Lean mass sparing in resistance-trained athletes during caloric restriction: the role of resistance training volume. European Journal of Applied Physiology. 10.1007/s00421-022-04896-5
Why general health is two sessions, and why beginners get the full dose. The ACSM position stand, drawn from 137 systematic reviews and over 30,000 participants, sets the baseline at all major muscle groups on two or more days a week, at 2-3 sets per exercise. That is the floor our general-health goal targets, and it is already what we prescribe - which is why a new account is not started on less.

Currier BS, D’Souza AC, Fiatarone Singh MA, Lowisz CV, Rawson ES, Schoenfeld BJ, Smith-Ryan AE, Steen JP, Thomas GA, Triplett NT, Washington TA, Werner TJ, Phillips SM (2026). American College of Sports Medicine Position Stand. Resistance Training Prescription for Muscle Function, Hypertrophy, and Physical Performance in Healthy Adults: An Overview of Reviews. Medicine & Science in Sports & Exercise. 10.1249/MSS.0000000000003745
Where the per-session ceiling comes from. Found returns stop being detectable at roughly 11 fractional sets for a single muscle in one session, which is the cap the app uses instead of a number we invented.

Remmert JF, Pelland JC, Robinson ZP, Hinson SR, Zourdos MC (2025). Is There Too Much of a Good Thing? Meta-Regressions of the Effect of Per-Session Volume on Hypertrophy and Strength. SportRxiv (preprint). source
Why effort matters, and why we flag it as a gap. Across 55 hypertrophy studies, growth increased as sets were taken closer to failure, while strength was largely indifferent. We do not record effort, so this is a known limitation rather than something the app models.

Robinson ZP, Pelland JC, Remmert JF, et al. (2024). Exploring the Dose-Response Relationship Between Estimated Resistance Training Proximity to Failure, Strength Gain, and Muscle Hypertrophy: A Series of Meta-Regressions. Sports Medicine. 10.1007/s40279-024-02069-2

What the evidence does not support

This is the part most fitness apps leave out. Our activation percentages are in-house estimates informed by movement mechanics and published EMG work. They are not laboratory measurements of your body, and one paper in particular sets the ceiling on how precisely they can be read:

THE LIMIT ON OUR OWN METHOD. Concludes that acutely measured surface EMG amplitude is not a validated predictor of muscle growth, and that the mechanical chain assumed between the two breaks down at several points. This is exactly why our activation percentages are banded into three coarse tiers for dosing instead of being used at face value - and why we show them to you rather than hiding them behind a score.

Vigotsky AD, Halperin I, Trybulski R, Vigotsky ED (2022). Longing for a Longitudinal Proxy: Acutely Measured Surface EMG Amplitude is not a Validated Predictor of Muscle Hypertrophy. Sports Medicine. 10.1007/s40279-021-01619-2

A set only counts if it is taken close enough to failure. We record weight and reps but not effort, so every logged set is counted as a hard set. If you stop well short, the app will over-credit you.
The per-workout dose for each goal, the beginner ramp and the third (0.25) tier are clinical judgements placed on the published dose-response curve. The papers give the curve; they do not give those numbers.
Activation percentages are reviewed in-house. No external trainer or laboratory has signed them off, and we say so rather than implying otherwise.

Why we publish this at all

The product exists because black-box workout generators ask you to trust a number you cannot inspect. Publishing only the research that flatters the model would be the same trick with extra footnotes. Every percentage is visible in the app, the method is on this page, and so is its ceiling.

Citations last checked 2026-08-07.