Count the sets from your last push workout. Four bench press, three overhead press, three tricep extensions. Your app says ten. A 67-study analysis says you're measuring with the wrong ruler — and your actual training volume is **30–50% higher** than the screen shows.
Your training app records every set the same way. A bench press set counts as one chest set. A row counts as one back set.
Simple. Clean. Wrong.
When the largest volume analysis ever published — pooling 67 studies and over 2,000 participants — tested this counting method against two alternatives, it lost. Not by a slim margin. The evidence ranged from strong to very strong across every outcome combination the researchers tested.
The method that won: fractional counting. A bench press doesn't just train your chest. It also works your triceps and your front delts. Fractional counting gives that indirect muscle work half the credit of a direct set. So your bench press counts as 1 chest set, but also as 0.5 tricep sets and 0.5 shoulder sets.
That sounds like a minor accounting change. It isn't.
Your 10-exercise push workout becomes 17 fractional sets spread across three different muscles. Your back day with rows, pull-ups, and deadlifts is delivering direct back stimulus plus a cascade of half-sets flowing into your biceps, rear delts, and forearms.
The practical shock: you've probably been doing more productive training than you realized. The anxiety about "am I doing enough?" was built on a ruler that systematically undercounted your work.
An earlier, smaller review using the old counting method had found a roughly linear relationship — more sets, more growth, no ceiling in sight. The larger analysis, using fractional counting, revealed what that cruder measurement had hidden: the returns start diminishing earlier and more steeply than the old numbers suggested.
The number everyone agreed on wasn't necessarily wrong. The unit of measurement was.
Where the Returns Drop
Once you're counting correctly, the next question lands: where exactly do the returns start falling off?
The first four fractional sets per muscle per week clear the minimum effective dose. That's where detectable growth begins. If you're doing compound exercises across three weekly sessions, you're likely already past this threshold.
From sets five through ten, each additional increment of growth costs roughly six more weekly sets. This is the highest-efficiency zone — full pay for every set you put in.
Then the rate changes.
Past ten sets, growth still happens — but each increment costs progressively more. By the upper range studied, you need nearly double the sets per growth increment compared to the sweet spot. The work goes up. The return holds. The efficiency drops.
The curve never hits zero. More volume still produced more growth across the entire range the evidence could measure. The probability that additional sets help was 100 percent.
But the cost per unit of growth climbed with every tier.
You're not overtraining. You're buying growth at a steeper and steeper price. The recovery cost of set twenty is identical to set one, but the growth it purchases is a fraction of what set five earned.
If you've been stressing about "junk volume" — the idea trending on TikTok and Reddit that your extra sets are worthless — the evidence doesn't support a cliff. There's no threshold where sets suddenly stop working. There's a slope that gets steeper. Whether the trade-off is worth it depends on how you recover and how much each additional fraction of growth matters to you.
And if you're wondering whether lighter weights change this prescription: they don't. The volume thresholds hold at any load, as long as sets go close to failure — a finding FitChef covers in a separate analysis of load and muscle growth.
Where Size and Strength Part Ways
Here's where the two goals stop agreeing.
Muscle growth keeps responding to more volume — slowly, but responding. Strength does not. Past a handful of sets, strength gains essentially stop.
The smallest detectable strength gain appeared at just one fractional weekly set. By roughly four sets, the curve hit a functional plateau. Additional volume beyond that didn't consistently improve how much weight you could lift.
Four sets.
Your sixteen-set leg day is doing two jobs at once. The first four sets build strength and size together. Sets five through sixteen keep building muscle — but they stopped moving the barbell somewhere around set four.
This doesn't mean you should train less. It means you should know what each set is actually doing. If your goal is getting stronger at specific lifts, the evidence points to a handful of focused sets and practicing those lifts often. If your goal is muscle size, more volume still pays at that declining rate.
Most people want both. Which means most people are running a strength program and a bodybuilding program simultaneously — whether they planned to or not.
The Argument That Didn't Matter
If you've spent any time in gym group chats or fitness YouTube, you've encountered the debate: full-body three times, upper-lower four times, or everything once per week with maximum volume per session?
The evidence says it barely matters for muscle growth.
Across 35 studies with over 1,000 participants, an extra weekly session was associated with a hypertrophy increase of just 0.32 percent — with the range of plausible values crossing zero. The probability that frequency has any positive effect was 91.3 percent, which sounds high until you realize the range included the possibility of no effect whatsoever.
Bro split, push-pull-legs, upper-lower, full-body — when total weekly volume is matched, the muscle growth is the same. How you distribute your sets across the week is a scheduling decision, not a biological one.
For strength, the story differs. More frequent practice of a specific lift showed a clear positive relationship — every additional weekly session was linked to a 3.27 percent strength improvement, with 100 percent probability.
But the mechanism likely isn't extra muscle stimulus. It's practice. Training a lift often is practice, not stimulus. The nervous system gets sharper at producing force in that pattern. The muscle itself doesn't need the repetition.
That explains the divide you see in the gym. Strength athletes repeat movements often — they're sharpening a pattern. Physique athletes spread their exercises wider — they're accumulating tissue stimulus. Both strategies match what the evidence found.
That debate is settled.
Your Number
Based on everything we examined across these studies, the evidence points to roughly ten fractional sets per muscle per week as the sweet spot — the zone where each set still earns meaningful growth without costing disproportionate recovery.
But you're probably already there.
Your training app just doesn't know it yet. A bench press is also half a tricep set and half a shoulder set. Your rows are half a bicep set. When you recount with fractional accounting, the program that looked like "not enough" might already be plenty.
Below four sets per muscle, the evidence suggests you're leaving growth on the table. Above ten, each additional set still contributes — just at a declining rate. And for strength, the curve flattens around four sets. Everything after that builds tissue but doesn't move the barbell.
The part we owe you: most participants in these studies were around 25 years old. The average study lasted about ten weeks. Whether these thresholds shift for someone in their forties or fifties — or over years instead of weeks — the studies we examined can't fully answer. The efficiency tiers are ranges, not rules. They tell you the neighborhood — not the house number.
Volume is one piece. Across seven research teams, nine conclusions, and over 9,350 participants, the training guide maps where volume sits alongside every other variable — and which ones turned out not to matter at all.
The half-set approximation — counting indirect work at exactly 50 percent — is also an estimate. A close-grip bench likely sends more than half its work to triceps. A cable row likely sends something other than exactly half to biceps. The value that fit the data best across all the studies was 0.5.
That makes the finding more useful, not less. The fundamental insight holds regardless: indirect work counts meaningfully but not equally. Your app currently scores it at zero.
Your training schedule is your call. The evidence says your muscles don't care how you arrange the calendar — the weekly total is what counts.
And if that weekly total is handled and your schedule is free — the question most people ask next is whether adding cardio will eat into the gains they just learned they already have.
Across 43 studies and over 1,000 participants, concurrent training produced zero measurable interference with muscle growth or maximal strength. FitChef's full analysis of the concurrent training evidence covers what that means for your programming.
The reader opens her training app after a push day. It says 10 sets across 3 exercises. She recounts: her 4 bench press sets are also 2 fractional tricep sets and 2 fractional shoulder sets. Her 3 overhead presses add 3 direct shoulder sets plus 1.5 fractional tricep sets and 1.5 fractional chest sets. Her 3 tricep extensions add 3 direct tricep sets. The app shows 10. Fractional accounting shows 17 muscle-specific sets across 3 muscles. Her actual volume is 70% higher than the screen displays. She's not undertraining — she was just reading the wrong ruler.