Between 8 and 12 repetitions per set is optimal for muscle growth, as we’ve been taught from childhood. Newer insights teach us that the number of repetitions doesn’t matter as much, as long as you train to near failure. However, a new study suggests there’s a minimum number of repetitions.

NUMBER OF REPETITIONS FOR MUSCLE GROWTH

As you can read in this article, you can achieve optimal muscle growth with both light and heavy weights. However, for practical reasons, you shouldn’t go too low or too high in weight, and therefore in rep range. The recommendation is somewhere between 6 and 30 repetitions.

This article explains that a high-repetition workout is unnecessarily taxing. Therefore, we’ll use 6-15 repetitions as a starting point.

MINIMUM NUMBER OF REPS

But what about that 6? Is that really the lower limit when it comes to hypertrophy (muscle growth)? A new study says no. It shows that sets of 3 to 5 repetitions are just as effective for hypertrophy as sets of 20 to 25 repetitions. A set of just 3 repetitions therefore provides the same growth stimulus, provided it’s trained to near failure.

This is especially good news for the powerbuilders among us, i.e., those who train for both muscle growth and strength.

BODYBUILDERS

If you’re a bodybuilder, we recommend you don’t go below 5 reps per set. There are some drawbacks to training with very heavy weights, as you can read here. If you can’t tolerate heavy weights at all, you can safely train with light weights.