How many reps per set? 2–6 for strength, 6–20 for size

The answer in two numbers: 2–6 for strength, 6–20 for size

Here's the short version your trainer would give you between sets.

For maximum strength, train heavy: 2–6 reps per set at ≥80% of your one-rep max. For muscle size — what exercise scientists call hypertrophy — the range is wider: anywhere from 6 to 20 reps works, as long as you push close to the point where you can't do another rep.

That's the finding from ACSM's 2026 position stand — a review that pooled 137 systematic reviews covering more than 30,000 participants. It's the ACSM's official position stand, updating their 2009 guidance through an overview of reviews (Currier et al., 2026).

The rest of this article explains why those numbers work — and what to do with them in your actual training.

137 systematic reviews. 30,000+ participants. The verdict: heavy loads for strength, moderate loads for size.

— Currier et al. (2026). ACSM Position Stand. Med Sci Sports Exerc.

How many reps and sets to build muscle (hypertrophy)

The biggest surprise from the research: rep range barely matters for muscle growth — as long as you're working hard enough.

Schoenfeld et al.'s 2017 meta-analysis — a review that pooled data from 21 studies — found no significant difference in muscle hypertrophy between low-load training (≤60% of your one-rep max, higher reps) and high-load training (>60% of your one-rep max, lower reps), when all sets were taken to failure (Schoenfeld et al., 2017).

Practically, that means a set of 20 bodyweight squats taken to the point where you genuinely cannot do another one produces similar muscle growth to a set of 6 heavy barbell squats taken to that same point.

What matters more than rep range is total weekly volume — the number of hard sets you do per muscle group. The ACSM overview found that ≥10 sets per week per muscle group drove more hypertrophy than lower volumes (Currier et al., 2026). For a deeper look at that number, see how many sets per muscle group per week.

For most people, a practical hypertrophy target is 3–4 sets of 8–15 reps per exercise, with 1–3 reps left in the tank at the end of each set.

How many reps and sets for strength

For raw strength — your one-rep max on the barbell squat, bench press, or deadlift — heavier loads win clearly.

The 2017 meta-analysis found gains in one-rep max strength were significantly greater with heavy loading (>60% 1RM) compared to light loading, even when muscle size gains were equal (Schoenfeld et al., 2017). This makes sense: strength is partly a skill. Your nervous system gets better at producing force when you practice producing force — and that means lifting heavy.

Schoenfeld et al.'s 2016 study of 19 resistance-trained men confirmed it head to head. The group training in the 2–4 rep range (heavy) gained significantly more squat strength than the group training in the 8–12 rep range — even though both groups did the same number of sets (Schoenfeld et al., 2016).

The ACSM position stand puts the strength threshold at ≥80% of your one-rep max — which works out to roughly 1–6 reps per set for most people (Currier et al., 2026).

Practical target for strength: 3–5 sets of 2–5 reps at 80–90% of your one-rep max, 2–3 times per week. See how many sets for strength for the set-count breakdown.

Strength is partly a skill. Heavy loads train your nervous system to produce force — not just your muscles.

— Schoenfeld et al. (2017). J Strength Cond Res.

How many sets and reps for hypertrophy — does the exact number matter?

Within the hypertrophy range, the specific rep count is less important than most people think. Anywhere from 6 to 30 reps can build muscle — the 2017 meta-analysis showed that clearly (Schoenfeld et al., 2017).

What the research does show is a sweet spot in practice. When sets aren't taken to failure, the moderate range (8–15 reps at 60–75% of your one-rep max) tends to be the most sustainable. Very high rep sets — 20–30 reps — produce similar muscle growth but require getting much closer to failure, and that fatigue adds up across a full workout.

The useful rule: pick a rep range you can execute with good form and push hard in. The research doesn't care whether that's 8 or 15 — your form and your effort level do.

6 to 30 reps all build muscle — if you push close enough to failure.

— Schoenfeld et al. (2017). J Strength Cond Res.

Progressive overload matters more than which rep range you pick

Here's something the rep-range debate misses: the biggest driver of muscle growth isn't your rep target — it's whether you're lifting more over time.

A 2026 RCT split 55 untrained women into two groups doing the same exercise (elbow extensions), the same sets (3), and the same rep target (8–12). One group progressively increased the load whenever they hit the top of the rep range. The other group kept the weight fixed.

After 8 weeks, triceps thickness grew 21.4% in the progressive group versus 11.3% in the fixed-load group (Kassiano et al., 2026). Same rep range. Same sets. The only variable was whether the weight went up.

This is why chasing a specific rep number — without tracking whether the weight is increasing — is one of the most common training mistakes. Your rep range sets the zone. Progressive overload is what makes it work. For more on that principle, see progressive overload training.

Same rep range, different weight progression: 21.4% growth with progressive load versus 11.3% without.

— Kassiano et al. (2026). Med Sci Sports Exerc.

How to structure your reps per set based on your goal

Here's the practical breakdown — no theory, just the numbers.

Goal: Maximum strength
- Rep range: 1–5 reps per set
- Load: ≥80% of your one-rep max
- Sets: 3–5 per exercise
- Frequency: ≥2 sessions per week per movement
- Source: Currier et al., 2026; Schoenfeld et al., 2016

Goal: Muscle size (hypertrophy)
- Rep range: 6–20 reps per set (8–12 is the practical sweet spot)
- Load: 60–80% of your one-rep max
- Sets: 3–4 per exercise, ≥10 sets per muscle group per week total
- Leave 1–3 reps in reserve at the end of each set
- Source: Currier et al., 2026; Schoenfeld et al., 2017

Goal: Both (general fitness)
- Rotate. Spend a few weeks in the 4–6 rep range, then a few weeks in the 8–12 range. You'll build both qualities without committing to a single extreme.

One universal rule across all goals: increase the load or reps over time. A rep range that never gets heavier produces less growth than one that does (Kassiano et al., 2026).