Purpose

Sarcopenia plays a principal role in the pathogenesis of frailty and functional impairment that occurs with aging. There are few published accounts which examine the overall benefit of resistance exercise (RE) for lean body mass (LBM), while considering a continuum of dosage schemes and/or age ranges. Therefore the purpose of this meta-analysis was to determine the effects of RE on LBM in older men and women, while taking these factors into consideration.

Methods

This study followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses recommendations. Randomized controlled trials and randomized or non-randomized studies among adults≥ 50 years, were included. Heterogeneity between studies was assessed using the Cochran Q and I 2 statistics, and publication bias was evaluated through physical inspection of funnel plots as well as formal rank-correlation statistics. Mixed-effects meta-regression was incorporated to assess the relationship between RE dosage and changes in LBM.

Results

Data from forty-nine studies, representing a total of 1328 participants were pooled using random-effect models. Results demonstrated a positive effect for lean body mass and there was no evidence of publication bias. The Cochran Q statistic for heterogeneity was 497.8, which was significant (p< 0.01). Likewise, I 2 was equal to 84%, representing rejection of the null hypothesis of homogeneity. The weighted pooled estimate of mean lean body mass change was 1.1 kg (95% CI, 0.9 kg to 1.2 kg). Meta-regression revealed that higher volume interventions were associated (β= 0.05, p< 0.01) with significantly greater increases in lean body mass, whereas older individuals experienced less increase (β=-0.03, p= 0.01).

Conclusions

RE is effective for eliciting gains in lean body mass among aging adults, particularly with higher volume programs. Findings suggest that RE participation earlier in life may provide superior effectiveness.