Why count sets per muscle at all
Past your first months of training, progress mostly follows one variable: how many serious sets each muscle gets per week. Not the number of exercises, not the hours spent in the gym. Just sets per muscle. If your shoulders stall, the first question worth asking isn't "which new exercise should I try", it's "how many sets did they actually get these past weeks". Most lifters can't answer it.
And counting by hand is harder than it looks. Does bench press count for triceps? Fully, half? Do warm-ups count? What about that drop set you threw in at the end? Do the exercise once in a spreadsheet, on a Sunday night, and you'll understand why nobody ever does it twice. Volume counting is exactly the kind of task humans do badly and abandon quickly, and that an app should do silently, on every set, without ever changing its convention.
The math, in plain sight
Plenty of apps show a "volume" number without ever saying how it's built. Gymmy does the opposite: one clear convention, applied automatically to every set you validate, and stated openly.
- Primary muscle: 1 set. A bench press set counts fully for the chest.
- Secondary muscles: 0.5. The same set counts half for triceps and front delts. Every exercise carries one primary muscle and up to three secondaries.
- Warm-ups: 0. A set marked as a warm-up stays out of your volume, just as it stays out of your records.
- Drop sets: 0.5. Logged, counted, but never inflated to the level of a real working set.
- Unvalidated sets: 0. A set you planned but didn't do doesn't exist for your stats.
None of this is a black box. The weighting is fixed, known, the same for everyone: when a bar says "12 chest sets per week", you know exactly how that number was built, and you can compare it week to week without wondering whether the method changed along the way. The set types you use mid-workout (warm-up, drop set) each carry their own weight in the math, with nothing extra for you to declare.
A weekly average, not a flattering total
Every serious benchmark is expressed in sets per muscle per week. That's the unit of the research literature, and of every useful conversation about volume. So Gymmy shows a weekly average, not a raw running total that mechanically grows over time and means nothing.
One detail that changes everything: the current month is never penalized. The total is divided by the weeks that have actually elapsed, not by a theoretical full month. On the 5th, your bars already reflect your real cadence; they aren't flattened by three weeks that haven't happened yet. Open the screen on any day and you read an honest number, directly comparable to your target.
And if you're wondering what to compare that number to, we wrote an honest summary of what the research says: how many sets per muscle per week. The two work together: the article gives you the ranges, your bars give you your reality.
Seven groups that expand into 19 muscles
"Back" is not a muscle. Lats and lower back can have radically different weeks, and a group average hides exactly what you'd need to see. Gymmy thinks in 19 fine muscles (upper, mid and lower chest, the three heads of the shoulder, lats, quads, hamstrings, calves, adductors, glutes, abs, obliques…), automatically rolled up into 7 broad groups.
On screen, that becomes bars per muscle group, readable in two seconds. And each group expands into its fine muscles: you discover that your "shoulders" are actually a lot of front delt and almost no rear delt, or that your "legs" volume is carried by the quads while the hamstrings coast. That's precisely the kind of imbalance an average masks and a drill-down reveals. And it's often the real answer to "why am I stalling".
What it changes, concretely
A few situations where these bars answer a real question:
- A muscle is stalling. First reflex: open its bars. Very often, the "mystery" of the plateau is simply a volume lower than you believed: the indirect work you were counting in your head weighed less than you remembered.
- You're changing programs. New split, new workouts. After two weeks, your bars tell you what the new layout actually delivers per muscle, not what it promised on paper. A badly balanced push-pull-legs shows up immediately.
- A busy stretch is coming. Less time, fewer workouts. The bars show you which muscles absorb the cut and which ones stay protected, so you trim deliberately instead of at random.
- You're coming back after a break. Your bars from the weeks before the break are still there, a factual snapshot of what "normal" looked like and a realistic reference for the ramp back up.
In every case, the pattern is the same: a decision that used to run on feel now runs on a number you never had to compute.
Zero extra logging
Everything starts in your exercise library: each exercise carries its primary and secondary muscles. Pick from the suggestion catalog and the muscles come pre-filled (still editable); create an exercise from scratch and you set them once, done forever.
From there, your normal logging does all the work: weight, reps, validate, next set. Weekly volume is a by-product of the log, not an extra form. Those same sets feed everything else in your progress too: your personal records caught live mid-workout, your per-exercise progress chart, and the recap of your week that puts the numbers next to last week's.
No double entry, no exports, no spreadsheet. If you log your workouts, you have your volume. That's it.
And how many sets "should" you do?
Gymmy won't tell you, and that's a deliberate choice. The app never prescribes: no set targets handed down, no "you're 4 back sets short this week", no auto-generated plan. Nobody, certainly not an app, knows your recovery, your sleep, your job, your other sports. An exact, honest number beats generic advice dressed up as science.
The division of labor is simple: Gymmy counts, you decide. You read your bars, compare them to the ranges in the volume article if you want a reference point, and adjust your week with full information: one more set here, an exercise moved there. It's exactly what an experienced lifter would do with a spreadsheet and discipline. Except here, the spreadsheet fills itself.
The best way to see your real bars is to log your real workouts. Your first 10 are free, no credit card required.
Frequently asked questions
How does Gymmy count a set for a muscle?
Every validated working set counts 1 for the exercise's primary muscle and 0.5 for each of its secondary muscles (up to three). A drop set counts 0.5, a warm-up counts 0, and an unvalidated set doesn't enter the math at all. The convention is fixed and transparent: you always know exactly where every bar in the chart comes from.
Do warm-ups count toward my training volume?
No. A set marked as a warm-up is excluded from volume, records and stats. That's deliberate: your sets-per-muscle bars should only reflect effective work, the sets that actually have a chance of driving progress. So warm up as much as you need without artificially inflating your weekly numbers.
Why a weekly average rather than a monthly total?
Because every useful benchmark is expressed in sets per muscle per week. That's the unit the research uses. Gymmy divides your total by the number of weeks that have actually elapsed, so the current month is never penalized: on the 5th, your bars are already accurate, not crushed by three weeks that haven't happened yet.
Does Gymmy tell me how many sets I should do?
No, never. Gymmy measures and displays, it doesn't prescribe. No targets handed down, no "you're 4 chest sets short". Only you know your recovery, your sleep and your life. If you want benchmarks, our article on weekly volume gives an honest summary of the research, and your bars tell you where you actually stand.