Higher volume resistance training enhances whole-body muscle hypertrophy in postmenopausal and older females: A secondary analysis of systematic review and meta-analysis of randomized clinical trials.

ABSTRACT

OBJECTIVE: This study explored the effects of resistance training (RT) volume on muscle hypertrophy in postmenopausal and older females. METHODS: This systematic review searched randomized controlled trials (RCTs) on PubMed/MEDLINE, Scopus, Web of Science, and SciELO. Studies with postmenopausal (age ≥ 45 y) or older females (age ≥ 60 y) that compared RT (whole-body) effects on muscle hypertrophy with a control group (CG) were included. Independently reviewers selected the studies, extracted data, and performed the risk of bias of RCTs (RoB2) and certainty of the evidence (GRADE). Whole-body lean mass, free-fat mass, and skeletal muscle mass measurements were included as muscle hypertrophy outcomes. A random-effects model standardized mean difference (Hedges'g), and 95% confidence interval (95%CI) were used for meta-analysis. RESULTS: Fourteen RCTs (overall RoB2 some concerns, except one study with high risk; GRADE low evidence) were included. RT groups were divided into low (LVRT, total volume 445.0 au) and high-volume (HVRT, total volume 997.3 au). Most exercises performed were arm curl, bench press or chest press, calf raise, leg curl, leg extension, leg press or squat, seated row or lat pulldown, and triceps pushdown. Both groups experienced muscle hypertrophy (HVRT = ∼1.3 kg vs. LVRT = ∼0.9 kg) when compared to CG, although HVRT demonstrated moderate effects size (HVRT = 0.52, 95%CI 0.27, 0.77) and LVRT demonstrated small effects size (LVRT = 0.34, 95%CI 0.14, 0.53). CONCLUSIONS: Compared to CG, results suggest that the HVRT protocol elicits superior improvements in muscle hypertrophy outcomes than LVRT in postmenopausal and older females.