There is no magic rep range

If you are a personal trainer, you probably default to 8-12 reps for most exercises. Ask why, and the answer comes automatically: "it's the hypertrophy zone." It is one of the most repeated ideas in any certification, any programming course, any gym conversation.

The problem is that the most robust meta-analyses of the last decade show that the rep range for hypertrophy does not work the way you were taught.

The "repetition continuum" solidified in the 1980s and 1990s: 1-5 reps for maximal strength, 8-12 for hypertrophy, 15+ for muscular endurance. The model was elegant and easy to teach.

Specificity of load does matter for maximal strength. But the mistake was assuming that what applies to strength applies equally to muscle size. That assumption survived decades. Until it was tested.

Schoenfeld, Grgic, and colleagues published a 2017 meta-analysis in the Journal of Strength and Conditioning Research comparing low-load (below 60% 1RM) and high-load (above 60%) resistance training. They included 21 studies, all taken to muscular failure.

The result for hypertrophy: no significant difference. The effect size was 0.03 — trivial, with confidence intervals crossing zero. It did not even approach the 0.20 threshold for a "small" effect.

For maximal strength, there was a difference: heavy loads produced greater 1RM gains. But for muscle growth, load range was not a determining factor.

In 2021, Schoenfeld published a re-examination of the repetition continuum in the journal Sports. The conclusion: muscular adaptations can be obtained — and in some cases optimized — across a broad spectrum of loading zones. The classic three-zone model is an oversimplification.

Greg Nuckols, in Stronger by Science, reviewed 20 studies comparing rep ranges with equated volume. Of those 20, 17 found no significant differences in hypertrophy. When total volume and proximity to failure are equalized, the number of reps per set carries less weight than we believed.

If rep range is not the primary factor, what is? A meta-analysis in Sports Medicine (2023) examined proximity to failure and hypertrophy. The relationship was non-linear: training close to failure was associated with greater growth, but reaching absolute failure is not necessary. Finishing sets with 1-2 reps in reserve (RIR) produced comparable results to training to complete failure in trained subjects.

This shifts the programming equation. Instead of asking "how many reps should I prescribe?", the operative question becomes "how close to failure does my client get on each set?"

The 8-12 range is not useless. It is convenient. It allows you to accumulate mechanical volume without the joint stress of very heavy loads or the extreme metabolic fatigue of 25-rep sets. For most compound exercises — squats, presses, rows — it is a comfortable zone that enables high effort with reasonable technique.

But using it as the only range is a programming error. A coach working with ten or twenty clients needs tools to solve different problems: a beginner who cannot tolerate heavy loads benefits from sets of 15-20 with good control; an advanced intermediate in a strength block needs sets of 4-6; a client with a joint injury may need light loads with long sets to stimulate muscle without stressing the joint.

When you have a platform that centralizes planning, progress tracking, and routine updates for every client, managing these different schemes stops being chaotic. You can see who is in which phase, what loads they handle, how volume is progressing — and adjust rep prescriptions with real context instead of defaulting to 3x10 for everyone.

The best strategy combines ranges. Nuckols summarizes it: do most of your training in the rep range that lets you accumulate the most hard sets per session, for each exercise and each muscle. That generally coincides with moderate loads — but not exclusively.

There is no sacred number. There are ranges that fit better for certain movements, certain clients, and certain phases. Hypertrophy happens across a broad spectrum of loading zones — as long as volume is sufficient and sets are taken close to failure.

A coach who masters the full spectrum has more tools to individualize, periodize, and solve specific problems. That is what separates a trainer who repeats templates from one who programs with intent.