Doing more sets of weightlifting each week helps you build more muscle, but after a certain point, doing even more sets doesn't help much more.
Scientific Claim
Higher weekly resistance training volume is associated with greater muscle hypertrophy in young, mostly male adults, with diminishing returns observed at higher volumes, suggesting there is an optimal range beyond which additional sets yield minimal further growth.
Original Statement
“The posterior probability of the marginal slope exceeding zero for the effect of volume on both hypertrophy and strength was 100%, indicating that gains in muscle size and strength increase as volume increases. However, both best-fit models suggest diminishing returns, with the diminishing returns for strength being considerably more pronounced.”
Evidence Quality Assessment
Claim Status
overstated
Study Design Support
Design supports claim
Appropriate Language Strength
association
Can only show association/correlation
Assessment Explanation
The study uses probabilistic language ('posterior probability') and acknowledges unknown randomization status, so causal verbs like 'increases' are inappropriate. The finding is correlational, not causal.
Evidence from Studies
Supporting (1)
The Resistance Training Dose Response: Meta-Regressions Exploring the Effects of Weekly Volume and Frequency on Muscle Hypertrophy and Strength Gains
More workouts with weights lead to bigger muscles, but only up to a point — after that, doing even more sets doesn’t help much more.