The Optimal Number of Reps for Forcing Muscle Growth

Focus more on HOW you lift to get the most out of each rep.

The Optimal Number of Reps for Forcing Muscle Growth
Kevin Horton

If you’ve been reading my articles and columns over the past 15 years, you are well aware that I believe very firmly in exposing each muscle to a very wide range of reps (but more specifically “tension times”), from as few as four all the way up to 50 or more (in a single set). This is the only way to tap into every growth mechanism and truly annihilate all muscle fibers along the continuum.

With that said, for the majority of lifters, the greatest percentage of work sets should keep the target muscle under tension for between 35 and 60 seconds. Now, what does that translate to in terms of reps? Well, that depends on what lifting tempo one is utilizing for each repetition. If you are lowering the weight in one second and without pause, and lifting it in one second (1/0/1 rep tempo), then you’ll need between 18 and 30 reps to reach optimal TUT (time under tension).

Sounds like a lot of repetitions for multiple sets, huh? Well, among other important reasons, this is precisely why it is best to slow things down, taking more time to move the weight from point A to B and back to A. If one were to lower the weight in four seconds, pause for one second at the midpoint, then raise the weight in one second, that would total six seconds per rep. You would require only six to 10 reps to achieve the necessary TUT to foster growth. Additionally, by slowing down the eccentric rep, you’ll damage muscle fibers, which will ignite hypertrophy.