Krieger · Journal of strength and conditioning research 2010 · meta-analysis · n=8 studies

Single vs. multiple sets of resistance exercise for muscle hypertrophy: a meta-analysis.

Level 1 - systematic review of randomized trials

Meta-analysis of comparative trials

PubMed 20300012 · doi:10.1519/JSC.0b013e3181d4d436 · record verified 2026-08-26

What was done

The authors conducted a multilevel meta-regression to compare the effects of single versus multiple sets per exercise on muscle hypertrophy. The dataset included 55 effect sizes nested within 19 treatment groups across 8 studies. Dose-response models evaluated outcomes across 1 set, 2–3 sets, and 4–6 sets per exercise, alongside sensitivity and publication bias analyses.

What was found

Multiple sets produced a significantly greater hypertrophy effect size (ES) than a single set (difference = 0.10 ± 0.04; 95% CI: 0.02 to 0.19; p = 0.016), corresponding to ~40% greater ESs overall. Mean effect sizes rose with volume: 0.24 for 1 set, 0.34 for 2–3 sets, and 0.44 for 4–6 sets. Compared to 1 set, standard regression trends favored 2–3 sets (difference = 0.09 ± 0.05; CI: -0.02 to 0.20; p = 0.09) and 4–6 sets (difference = 0.20 ± 0.11; CI: -0.04 to 0.43; p = 0.096); both reached significance under permutation testing (p < 0.01). The difference between 2–3 sets and 4–6 sets was not statistically significant (difference = 0.10 ± 0.10; CI: -0.09 to 0.30; p = 0.29).

Why it matters

This analysis established quantitative evidence that multi-set resistance exercise routines yield superior muscle hypertrophy compared to single-set protocols across both trained and untrained individuals.

Limits

The meta-analysis was constrained by a small evidence base of only 8 studies. Total participant numbers, participant demographics, specific measurement techniques for hypertrophy, exercise selection, and training intensity/frequency were not reported in the abstract. Comparisons between higher volume tiers (2–3 vs. 4–6 sets) had wide confidence intervals and lacked statistical power to confirm a clear difference.

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