Sex Differences in Resistance Training: A Systematic Review and Meta-Analysis.
Level 1 - systematic review of randomized trials
Systematic review and meta-analysis of comparative intervention trials
PubMed 32218059 · doi:10.1519/JSC.0000000000003521
What was done
A pre-registered systematic review and meta-analysis (PROSPERO CRD42018094276) evaluated whether young to middle-aged males and females exhibit different strength or hypertrophy responses to identical resistance training protocols. Meta-analyses were performed using robust variance random-effects modeling for multilevel data structures with small-sample adjustments.
What was found
Hypertrophy (12 outcomes, 10 studies) showed no significant difference between males and females (ES = 0.07 ± 0.06; P = 0.31; I² = 0). Upper-body strength (19 outcomes, 17 studies) showed a significant effect favoring females (ES = -0.60 ± 0.16; P = 0.002; I² = 72.1). Lower-body strength (23 outcomes, 23 studies) showed no significant difference between sexes (ES = -0.21 ± 0.16; P = 0.20; I² = 74.7).
Why it matters
This review shows that relative muscular hypertrophy and lower-body strength gains occur at similar magnitudes in males and females, though females may experience larger relative upper-body strength improvements.
Limits
The total participant count was not reported in the abstract. Strength analyses exhibited high statistical heterogeneity (I² > 72%). Included studies were of short duration, and the abstract notes uncertainty regarding whether upper-body findings were driven by neural, muscular, motor learning factors, or baseline status.
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