The belief that men and women require fundamentally different resistance-training programs is widespread. Hormonal differences, particularly testosterone, are often cited as justification. While these biological differences clearly affect absolute muscle mass and strength, the more relevant question for program design is whether they alter how the body adapts to resistance training.
When training programs are matched for volume, intensity, and progression, the evidence consistently shows that men and women demonstrate similar relative adaptations in strength and hypertrophy.
Men generally begin resistance training with greater absolute strength and lean mass, especially in the upper body. This difference is well documented and largely attributable to greater muscle cross-sectional area and androgen exposure (Miller et al., 1993; Haizlip et al., 2015).
What matters for training, however, is not baseline capacity but the relative change from baseline in response to a training stimulus.
Multiple controlled trials have shown that when men and women follow the same resistance-training program, both groups experience significant increases in strength.
Gentil et al. (2016) reported that untrained men and women completing the same 10-week program achieved similar relative increases in upper-body strength, despite men maintaining higher absolute strength values.
These findings have been reinforced by later analyses. A systematic review and meta-analysis by Roberts et al. (2020) found that effect sizes for strength gains were comparable between sexes when training variables were equated. Some studies even observed slightly greater relative upper-body strength gains in women, likely reflecting lower starting values and greater neural adaptation early in training.
The same pattern emerges when muscle size is measured directly.
Abe et al. (2000) demonstrated that men and women following identical full-body resistance programs experienced similar proportional increases in muscle thickness across multiple anatomical sites.
Recent analyses have shifted away from asking whether men gain more muscle and toward asking whether muscle tissue itself is differently responsive. Across modern reviews, there is little evidence that sex meaningfully alters the relative hypertrophic response to resistance training. The hypertrophic response to mechanical tension and progressive overload appears remarkably similar between sexes when training variables are matched (Haun et al., 2023; Roberts et al., 2020).
Recent meta-analytic work has shifted away from asking whether men gain more muscle and toward asking whether muscle tissue itself is differently responsive. Across modern analyses, the answer appears to be no. The hypertrophic machinery responds similarly to mechanical tension and training volume in both sexes.
Testosterone influences maximal muscle mass potential. However, resistance training increases muscle protein synthesis in both men and women, and the relative anabolic response to training appears similar within normal physiological ranges (Phillips, 2014; Haizlip et al., 2015).
Estrogen may even exert protective effects on muscle damage and recovery, although this has not been shown to require different program structures in practice (Enns & Tiidus, 2010).
Not exactly. They mean that sex alone is a poor justification for different programming.
More meaningful variables include:
Two men may require very different programs. Two women may respond optimally to the same one. Sex does not override individual response.
Good training principles work because they are physiologically sound, not because they are gendered.
Abe, T. et al. (2000). Time course for strength and muscle thickness changes following upper and lower body resistance training in men and women. European Journal of Applied Physiology, 81(3), 174–180. PubMed.
Enns, D. L. and Tiidus, P. M. (2010). The influence of estrogen on skeletal muscle: Sex matters. Sports Medicine, 40(1), 41–58. PubMed.
Gentil, P. et al. (2016). Comparison of upper body strength gains between men and women after 10 weeks of resistance training. PeerJ, 4, e1627. PubMed.
Haizlip, K. M. et al. (2015). Sex-based differences in skeletal muscle kinetics and fiber-type composition. Physiology, 30(1), 30–39. PubMed.
Haun, C. T. et al. (2023). Inter-individual variability in resistance training-induced muscle hypertrophy: A review. Sports Medicine, 53(1), 1–20. PubMed.
Miller, A. E. J. et al. (1993). Gender differences in strength and muscle fiber characteristics. European Journal of Applied Physiology, 66(3), 254–262. PubMed.
Phillips, S. M. (2014). A brief review of critical processes in exercise-induced muscular hypertrophy. Sports Medicine, 44(Suppl 1), S71–S77. Pubmed.
Refalo, M. C. et al. (2025). Sex differences in absolute and relative changes in muscle size following resistance training: A systematic Bayesian meta-analysis. Sports Medicine. PubMed.
Roberts, B. M. et al. (2020). Sex differences in resistance training adaptations: A systematic review and meta-analysis. Journal of Strength and Conditioning Research, 34(5), 1448–1460. PubMed.
Schoenfeld, B. J. et al. (2021). Strength and hypertrophy adaptations between low- vs. high-load resistance training: A systematic review and meta-analysis. Journal of Strength and Conditioning Research, 35(1), 1–13. PubMed.