When men and women in their late teens to mid-40s do strength training, they both gain muscle at about the same rate—men might gain a tiny bit more, but it’s so small it doesn’t really mean one sex builds muscle better than the other.
Claim Language
Language Strength
probability
Uses probability language (may, likely, can)
The claim uses 'leads to' and 'indicating', which suggest likelihood or inference rather than certainty. 'Similar' and 'comparable' further soften the assertion, implying a probabilistic conclusion based on data (e.g., HDI range includes zero), not a definitive causal claim.
Context Details
Domain
exercise_science
Population
human
Subject
Healthy adults aged 18–45
Action
leads to
Target
similar relative increases in muscle size between males and females, with a 0.69% higher average percentage gain in males
Intervention Details
Gold Standard Evidence Needed
According to GRADE and EBM methodology, here is what ideal scientific evidence would look like to definitively prove or disprove this specific claim, ordered from strongest to weakest evidence.
Evidence from Studies
Supporting (1)
Sex differences in absolute and relative changes in muscle size following resistance training in healthy adults: a systematic review with Bayesian meta-analysis
The study found that when men and women do the same strength training, their muscles grow at about the same rate relative to how big they were at the start — so neither sex has a big advantage in building muscle size.