This study aimed to examine the current state of the field regarding anabolic resistance of aged skeletal muscle in response to resistance exercise, using a meta-analytic approach. By integrating data across multiple studies, we sought to provide a more comprehensive and statistically powerful analysis of age-related differences in skeletal muscle adaptation to resistance exercise.
We conducted a systematic review and meta-analysis of peer-reviewed literature published up to July 2024, reporting skeletal muscle response to resistance exercise protocols in young and older adults. Inclusion criteria encompassed studies reporting on resistance exercise protocols in both young and older adult populations. We extracted data on muscle strength and muscle mass outcomes. Random-effects meta-analysis was used to compute summary estimates, with outcomes stratified by sex.
The analysis included 12 studies, comprising 273 young adults and 290 older adults. Muscle strength was primarily evaluated through upper and lower limb strength tests (e.g., chest press, leg press), while muscle mass was assessed using various methods including MRI and DXA scans. Aged lower limb skeletal muscle displayed blunted strength gains compared to young counterparts. The age-related decline in skeletal muscle anabolic response was sex-specific, with aged females displaying more pronounced blunted muscle strength gains compared to male counterparts. Regarding muscle mass, although older adults showed a trend towards less improvement, the difference did not reach statistical significance.
This meta-analysis demonstrates that skeletal muscle response to resistance exercise protocols varies in an age- and sex-dependent manner, particularly for muscle strength gains. The findings suggest the need for developing sex-specific intervention strategies to promote skeletal muscle health in older populations. The more pronounced anabolic resistance in older females highlights the importance of targeted approaches for this demographic.
Understanding the age-related decline in skeletal muscle anabolic responses to resistance exercise protocols can inform the development of more effective, tailored interventions to counteract anabolic resistance in aged skeletal muscle. This knowledge can guide the design of optimized resistance training programs that account for age and sex differences, potentially improving mobility, reducing fall risk, and enhancing overall quality of life in older adults. Future research should focus on elucidating the molecular mechanisms underlying these age- and sex-specific differences to develop targeted pharmacological and lifestyle interventions that can complement resistance exercise in older populations.
Sex differences
Aging
