Abstract
The demographic transition makes it necessary to establish new recommendations about the components that are most affected by aging, such as: muscle mass, fat mass, bone mass, muscle strength, and physical performance. Exercise has been identified as a factor that improves those conditions. The aim of this review is to synthetize and analyze the results of exercise interventions on muscle mass, fat mass, bone mass, strength and physical performance in community dwelling older adults (OA). A systematic search was carried out in eleven databases, using validated terms as "aged", "exercise" and others. For the meta-analysis, we differentiated by type of exercise and outcome. Twenty-nine randomized clinical trials were obtained for the review and 24 clinical trials for meta-analysis. This study identified an increase of 1.0 kg (95% Confidence Interval [CI] 0.3 -1.7) in total muscle mass (TMM) and 0.4 kg (95%CI 0.0,0.7) in appendicular muscle mass (AMM); a decrease of -3.7 kg (95% CI -5.8, -1.5) in total fat mass and -3.7% (95%CI -5.8, -1.5) in fat percentage after the resistance exercise intervention by 2-3 times per week. A -3.0% (95%CI -4.6, -1.3) decrease was observed in fat percentage after the aerobic exercise intervention. The quality of the evidence was ranked from high to very low; the risk of bias most common was performance bias and other bias. This study suggests that resistance exercise is the intervention that shows a positive effect on muscle fat mass, and bone mass. More research is needed for other exercise interventions.