Rep ranges: how many reps for muscle and strength

The tidy old rule

For decades the rule of thumb was neat: low reps for strength, 8 to 12 for muscle, high reps for endurance. A review that re-examined this "repetition continuum" in 2021 concluded that current research fails to support some of its central assumptions¹.

Muscle grows across the range

When studies compare light and heavy loads with hard sets, muscle growth comes out about the same. A 2017 meta-analysis found that hypertrophy can be achieved equally across a spectrum of loading ranges², and a 2023 network meta-analysis found that every prescription it compared promoted growth comparably³.

The condition matters: those sets were hard. In the 2017 analysis every set went to failure. You do not have to go that far, as a 2023 meta-analysis found no advantage for training to failure over stopping short of it⁴. But a set of 20 that stops ten reps early is not the same set as one that stops two reps early.

Strength is different

Strength does care about load. The same 2017 analysis found that maximal strength benefits from heavy loads, and a 2021 network meta-analysis put it plainly: muscle growth seems to be independent of load, while strength gains are greater with high loads⁵. If you want a heavier single, you have to practise heavy sets.

How to pick a range

Since growth is not tied to one range, choose by what the range has to do: leave room to progress, and fit the lift. Heavy lifts such as the squat or the deadlift work well in lower ranges, around 5 to 8, where 2.5 kg is a small step. Small lifts such as the lateral raise work better in 12 to 20, because their steps are coarse and reps are the fine-grained progress they allow.

Keep the range wide enough to climb in, four or five reps is common, and keep it once you have picked it. A range you change every month never gets climbed. Double progression is the method that puts one to work.