How many sets per muscle per week, and who that number was for

Ten to twenty sets per muscle group per week. You have seen the number, probably more than once, usually stated without a source and always without a caveat.

It comes from a real review of real studies. It is also narrower than almost anyone repeating it lets on, it describes a different curve for strength than for size, and it is swamped by how differently individual people respond to the same program.

Where the number actually comes from

A 2022 systematic review concluded that twelve to twenty weekly sets per muscle group was a reasonable standard recommendation. That is the source of the figure in circulation.

Its scope, stated by the authors and dropped by nearly everyone since: young, resistance-trained men with at least a year of experience, in interventions of six weeks or more, using direct measures of muscle thickness or cross-sectional area. If you are new to lifting, or not a young man, the number was not derived from anyone like you.

The dose-response curve, and what it does not say

The most-cited work here is a 2017 meta-analysis that found each additional weekly set was associated with roughly a 0.37% greater gain. That is a real effect and a small one.

It is also the single most misquoted paper in volume discussions. Its highest volume category was ten or more sets. It did not compare twenty sets with ten, and it did not identify a plateau. Any article telling you that this analysis showed twenty sets is optimal is describing something the analysis could not have found.

A 2026 meta-regression is the better current estimate. Pooling around 220 hypertrophy and 490 strength effects, it estimated about a 0.24% hypertrophy increase per additional set at an average weekly volume of roughly twelve sets. Two findings from it are worth carrying:

• Hypertrophy keeps rising with volume, with mild diminishing returns.
• Strength does not. It shows strong diminishing returns and effectively plateaus at moderate volumes.

That analysis also counted sets as direct or indirect relative to the muscle being measured, which materially changes the numbers compared with older reviews. If you count every set of rows as a full set for biceps, you are not counting the way the better evidence counts.

Strength and size are different questions

The largest synthesis in this area, a Bayesian network meta-analysis covering 178 strength studies and 119 hypertrophy studies with over 8,000 participants between them, and unusually well balanced by sex, found that higher loads above 80% of one-rep max maximized strength, while all prescriptions promoted hypertrophy comparably.

Put that beside the volume curves and a simple picture emerges. If you want to get stronger, load and specificity do most of the work and piling on sets stops paying quite quickly. If you want to get bigger, volume matters more and keeps mattering for longer, and how heavy is much less important than people assume.

The part that should make you suspicious of any single number

A study of 287 previously untrained people aged 19 to 78 put everyone through the same program and measured what happened. Average muscle size change was about 4.8%. The range was minus 11% to plus 30%. Average strength change was 21%, with a range of minus 8% to plus 60%. Age and sex did not explain the spread.

Some people on an identical program roughly tripled the average response. Some went backward. That variance is far larger than the difference between any two sensible weekly set counts, which is the strongest argument against treating a prescribed number as anything other than a starting point.

The lower bound is lower than you think

For strength specifically, a meta-analysis on the minimum effective dose in resistance-trained men found that the bottom end of the dose-response is considerably lower than volume-maximalist content implies. It is a small evidence base and it looked at one-rep-max strength only, with no hypertrophy outcome, so do not stretch it. But it is a useful counterweight when everything you read pushes upward.

A workable summary

Somewhere around ten to twenty weekly sets per muscle group is a defensible place to start if you are a trained lifter chasing size, because that is roughly the population the recommendation came from. Fewer sets and heavier loads is the better shape if strength is the goal, because the strength curve flattens earlier. Below that, almost anything beats nothing, and the minimum effective dose for strength is genuinely modest.

And whatever number you pick, the honest position is that the between-person variation is bigger than the between-program variation. That is not a reason to stop counting. It is a reason to count your own sets and watch your own results, rather than treating someone else’s average as a prescription.