Sex Differences in Adaptations in Muscle Strength and Size Following Resistance Training in Older Adults: A Systematic Review and Meta-analysis.
Level 1 - systematic review of randomized trials
Systematic review and meta-analysis of comparative intervention studies
PubMed 33332016 · doi:10.1007/s40279-020-01388-4
What was done
A systematic review and meta-analysis searching five databases (Web of Science, Science Direct, SPORTDiscus, CINAHL, MEDLINE) from inception to June 2020. Included studies evaluated males and females over 50 years old performing identical resistance training protocols with muscle strength or size outcomes. Study quality was appraised using a modified Downs and Black checklist.
What was found
Thirty studies (41 comparison groups, 1410 participants: 651 males, 759 females; mean quality score 14.7/29) were analyzed. Relative gains: Females gained significantly more relative lower-body strength than males (g = -0.21 [95% CI -0.33, -0.10], p = 0.0003), while relative upper-body strength (g = -0.29 [95% CI -0.62, 0.04], p = 0.08) and relative muscle size (g = 0.10 [95% CI -0.04, 0.23], p = 0.16) showed no significant sex differences. Absolute gains: Males gained significantly more absolute upper-body strength (g = 0.48 [95% CI 0.09, 0.88], p = 0.016), absolute lower-body strength (g = 0.33 [95% CI 0.19, 0.47], p < 0.0001), and absolute muscle size (g = 0.45 [95% CI 0.23, 0.66], p < 0.0001).
Why it matters
It demonstrates that whether sex differences appear to exist in older adults' resistance training adaptations depends almost entirely on whether outcomes are measured in absolute or relative terms.
Limits
The average methodological quality of included studies was only moderate (14.7/29). The abstract does not detail training duration, intensity, specific measurement modalities for muscle size, or dietary controls across the included trials.
Cited by
- supports Relative to starting one-rep max, women gain a similar or slightly higher percentage of strength compared to men from resistance training.