Training volume: how many sets do you actually need?
More sets build more muscle, but each extra set buys less than the last — and strength stops paying out far sooner than size does.
Ask how many sets you should do and you will usually get a number: ten a week, or twelve to twenty, or “as many as you can recover from”. Each of those has a study behind it. None of them is wrong, exactly. But each is a point taken from a curve, and the shape of the curve is more useful than any single point on it.
The short version is that volume works, that it works with sharply diminishing returns, and that it works very differently for muscle size than for strength. The longer version explains why a lifter doing a third of the sets of the person next to them can be gaining strength just as fast.
What counts as a set
“Volume” means two different things, and mixing them up causes most of the confusion.
The older meaning is volume load: sets × reps × weight. Five sets of ten at 60 kg is 3,000 kg. It is useful for tracking a single lift over time, but it is a poor way to compare programmes, because it rewards light weights and high reps. Doubling the reps at half the weight leaves volume load unchanged and produces a completely different session.
The research this article draws on counts something simpler: sets per muscle per week. That is the dose in every study below. It only works as a measure because the sets being counted are hard. In the trials that built the evidence, most sets were taken to or near failure — in the largest pooled analysis, about 78 per cent of the effects for muscle size came from protocols with some definition of failure, though only about 30 per cent defined it clearly. 2 A set that ends ten reps short of failure is not the same dose as one that ends two short, and counting them the same would make the whole measure meaningless.
That matters most for muscle size. An analysis pooling studies that varied proximity to failure found that growth increased as sets were stopped closer to failure, while strength gains were similar across a wide range of reps in reserve. 5 The authors are careful to call the analysis exploratory, because how close each set came to failure had to be estimated from study descriptions rather than measured. If you train by RPE, the practical translation is in our guide to reps in reserve: most working sets at two or three reps short of failure count as hard sets.
There is a second counting problem. A bench press trains the chest directly, but the triceps and front shoulders work too. Does a set of bench press count as a set for the triceps? The 2025 meta-regression tested three answers — count indirect sets as a full set, as half a set, or not at all — and found the data fitted best when a set for a muscle that assists, rather than drives, the movement counted as half a set. 2 The authors call this a heuristic for modelling, not a rule, and say the right weighting probably varies by exercise. But it is a sensible default: four sets of rows are roughly two sets for your biceps.
The dose-response curve
The modern case for volume starts with a 2017 meta-analysis by Brad Schoenfeld and colleagues. Pooling 15 studies and 34 training groups, it found that each additional weekly set was associated with about 0.37 percentage points more muscle growth. 1 Grouped into bands, fewer than five weekly sets per muscle produced an average gain of 5.4 per cent, five to nine sets 6.6 per cent, and ten or more 9.8 per cent.
That last comparison is the source of the widely repeated “ten sets a week” figure, and it is weaker than its fame suggests. The difference between the three bands was a trend, not a statistically significant result (P = 0.074). When the authors removed one influential study — a six-month trial in which the highest-volume group did 30 sets a week — the advantage of ten-plus sets over five to nine disappeared, and the per-set effect fell to 0.25 percentage points. 1 Only two of the fifteen studies used people with lifting experience, and so few groups did more than twelve weekly sets that the authors said they could not tell where the benefit levelled off. Their own reading was balanced: low-volume training of four or fewer weekly sets still produced substantial growth, and more volume produced more.
Eight years and many more trials later, a 2025 meta-regression from Florida Atlantic University pooled 67 studies and 2,058 participants and tested what shape the relationship takes, rather than just whether more is better. 2 For muscle size, the best-fitting curve showed growth rising with volume but flattening as it went. The authors expressed this as the number of extra sets needed for each additional increment of growth large enough to be detected over measurement error:
| Weekly sets (half-counting indirect) | Extra sets needed for each further detectable gain |
|---|---|
| About 4 | The minimum that produced detectable growth |
| 5–10 | About 6 |
| 11–18 | About 8.5 |
| 19–29 | About 10.75 |
| 30–42 | About 12.5 |
| 43 and above | Too few studies to say |
Read the table as a price list. The first few sets buy a lot. By the high twenties you are paying nearly twice as many sets for the same increment. The curve never actually stopped rising in their data, but the authors stress that few studies tested more than about 25 sets, so the upper end is uncertain — it is compatible with a plateau, or even with too much volume becoming counterproductive. 2
Strength is a different curve
The most useful single study on this question is Schoenfeld’s 2019 trial in trained men, because it tested very different volumes on people who already lifted. 3 Forty-five men averaging four years of lifting experience started, and thirty-four completed eight weeks of a seven-exercise full-body programme, three times a week, with every set taken to failure in the 8–12 rep range. The only difference between groups was sets per exercise: one, three or five. For the legs, that came to 9, 27 and 45 weekly sets.
Muscle growth followed the dose. The five-set group gained significantly more thickness than the one-set group at the front of the thigh, the outer thigh and the elbow flexors. 3
| Item | Low | Estimate | High |
|---|---|---|---|
| 9 sets a week | 1.6 | 3.1 | 4.5 |
| 27 sets a week | 3.5 | 4.9 | 6.3 |
| 45 sets a week | 5.2 | 6.8 | 8.3 |
Strength did not. Squat and bench press gains showed no significant difference between groups, and the statistical evidence favoured no difference for the squat. 3
| Item | Low | Estimate | High |
|---|---|---|---|
| 9 sets a week | 13.7 | 18.6 | 23.4 |
| 27 sets a week | 9.5 | 14.1 | 18.7 |
| 45 sets a week | 14.9 | 19.5 | 24.0 |
The practical consequence is in the session lengths the paper reports: about 13 minutes for one set per exercise, 40 for three and 68 for five. 3 For strength, the shortest programme was as good as one more than five times as long. The authors did note limits: the study was slightly underpowered after eleven dropouts, it lasted eight weeks, it used moderate rep ranges rather than heavy strength-specific ones, and most of the men had not been training to failure before, so the change itself may have been a stimulus.
The 2025 meta-regression points the same way, and more strongly. 2 For strength, a single weekly set of the tested exercise — counting closely related exercises as half — was enough to produce a detectable gain, and further detectable improvements stopped at around four sets. Beyond that, extra volume did not consistently add gains larger than measurement error: in the authors’ words, a functional plateau. Two caveats apply. Their threshold for a detectable strength gain was nearly 4 per cent, which is a lot to a powerlifter, so smaller benefits beyond four sets may well exist. And the authors suspect many participants were tested on lifts they had not practised much, so early gains partly reflect learning the movement.
The idea that ties this together is progressive overload: you keep improving by gradually asking more of the body over time, through heavier loads, more reps or more sets. For strength, the pooled data suggest that practising the lift more often pays off more reliably than piling on sets: weekly frequency had a clear positive effect on strength, with diminishing returns, while it made little measurable difference to muscle size. 2 For size, adding sets is one of the levers that keeps working longest.
Where the popular numbers come from
Three numbers circulate, and each is worth knowing the source of.
“At least ten sets a week.” This is the practical recommendation of the 2017 meta-analysis. 1 As above, it rests on a trend that lost its advantage when one study was removed, from a pool in which only two of fifteen studies used experienced lifters. It is a reasonable target, not a threshold.
“Twelve to twenty sets a week.” This comes from a 2022 review that compared moderate (12–20) with high (more than 20) weekly volumes in young, trained men. 4 It included seven studies, six of them in the pooled analysis. Higher volume produced significantly more growth in the triceps, but not in the quadriceps (P = 0.19) or biceps (P = 0.59). The authors concluded that 12 to 20 sets may be an optimal standard recommendation. Notice what that conclusion rests on: a failure to find a difference in two muscles across a handful of small studies. That is absence of evidence, not evidence of a ceiling — and the pooled estimates for both muscles still leaned towards the higher volumes.
“Forty-five sets.” The highest volume in the 2019 trial produced the most leg growth. 3 It also took over an hour per session, three times a week, and was tested for eight weeks. That is evidence that very high volume can work in the short term for young trained men, not that it is sustainable or wise for anyone else.
Two things none of these studies tell you are worth stating plainly.
Who was studied. The 2025 analysis was 79 per cent male with an average age of 25, and it excluded adults over 70. 2 The 2019 trial was entirely young men. 3 The 2017 analysis did include women and older adults and found no evidence that they responded to volume differently — but with only fifteen studies, the absence of a difference is weak evidence. 1
What high volume costs. The 2025 authors say directly that they did not examine injury, sustainability or burnout, and point out that every participant in their data had to tolerate the programme well enough to finish it. 2 Studies averaged about ten weeks. Two of the eleven dropouts in the 2019 trial left with training-related injuries; the paper’s text does not break them down by group. 3 The upside of more sets is measured carefully. The downside largely is not.
The bottom line
The evidence supports a simple way of thinking about sets, rather than a number to hit.
For strength, a few hard weekly sets of the lift you want to improve get most of the benefit. If progress stalls, practising the lift more often is a better-supported next step than adding sets.
For muscle size, about four hard sets per muscle per week is enough to make progress, and somewhere around ten is a sensible place for most people to sit. More can work, but each extra set buys less than the one before, and above the mid-twenties the evidence gets thin.
For everyone, add volume gradually and judge it by results: whether your lifts and measurements are moving, and whether you recover between sessions. If they stall and you are recovering well, a few more sets is a reasonable next step. If you are not recovering, more sets are not the answer. The best volume is the one you can repeat for months, not the one that won an eight-week study.
- Schoenfeld BJ, Ogborn D, Krieger JW. Dose-response relationship between weekly resistance training volume and increases in muscle mass: a systematic review and meta-analysis. J Sports Sci, 2017;35(11):1073-1082.Checked against the original
- Pelland JC, Remmert JF, Robinson ZP, Hinson SR, Zourdos MC. The resistance training dose response: meta-regressions exploring the effects of weekly volume and frequency on muscle hypertrophy and strength gains. Sports Med, 2026;56(2):481-505.Checked against the original
- Schoenfeld BJ, Contreras B, Krieger J, Grgic J, Delcastillo K, Belliard R, Alto A. Resistance training volume enhances muscle hypertrophy but not strength in trained men. Med Sci Sports Exerc, 2019;51(1):94-103.Checked against the original
- Baz-Valle E, Balsalobre-Fernández C, Alix-Fages C, Santos-Concejero J. A systematic review of the effects of different resistance training volumes on muscle hypertrophy. J Hum Kinet, 2022;81:199-210.Checked against the original
- Robinson ZP, Pelland JC, Remmert JF, Refalo MC, Jukic I, Steele J, Zourdos MC. Exploring the dose-response relationship between estimated resistance training proximity to failure, strength gain, and muscle hypertrophy: a series of meta-regressions. Sports Med, 2024;54(9):2209-2231.Checked against the original
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This article has not been reviewed by a credentialed professional. It was researched and written from the primary sources listed below, but a reviewer catches things citations cannot — omitted contraindications, misread effect sizes, and questions of emphasis. We would rather tell you that than imply a review that did not happen.
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