Systematic review and meta-analysis of the effects of exercise in older adults with sarcopenia.

Aging is associated with progressive physiological changes that impair physical functioning and quality of life (QoL), as exemplified by sarcopenia, a condition characterized by the loss of skeletal muscle mass and strength that increases the risk of falls, dependency, and mortality. Although physical exercise is widely recognized as an effective intervention, the literature remains heterogeneous with respect to the most appropriate modalities for this population. This study aimed to synthesize evidence from randomized controlled trials investigating the effects of physical exercise on skeletal muscle mass, muscle strength, physical performance, QoL, and mortality in older adults with sarcopenia. A systematic search was conducted in PubMed, Embase, CENTRAL, Web of Science, CINAHL, PEDro, SPORTDiscus, and LILACS databases, with no restrictions on language or publication date, up to May 26, 2025. The methodological quality of included studies was assessed using the PEDro scale. Meta-analyses were performed using standardized mean difference or mean difference for post-intervention data, and the certainty of evidence was graded according to the GRADE approach. Sensitivity analyses evaluated the impact of studies with a high risk of bias, and subgroup analyses compared different exercise modalities and diagnostic criteria for sarcopenia. Following systematic screening, 72 studies were included, of which 36 were classified as having a low risk of bias. Physical exercise was superior to control conditions in improving skeletal muscle mass (small effect size), muscle strength, and physical performance (moderate effect size), with no significant effects on QoL. Resistance exercise was more effective than aerobic exercise for increasing skeletal muscle mass (large effect size). The combination of physical exercise and nutritional supplementation yielded greater benefits than either intervention alone for muscle mass and strength and, in sensitivity analyses, also for physical performance. A meta-analysis for mortality was not performed, as only one RCT reported this outcome, representing very limited evidence that precludes any meaningful pooled estimate or definitive conclusions regarding the effects of exercise on mortality in this population. Subgroup analyses stratified by diagnostic criteria demonstrated overall consistent effects across the different sarcopenia definitions. The certainty of evidence ranged from very low to moderate. Physical exercise should be considered a first-line intervention for older adults with sarcopenia, given its potential to improve skeletal muscle mass, muscle strength, and physical performance, supported by moderate-certainty evidence. The effects of exercise combined with nutritional supplementation and the comparative effectiveness of different exercise modalities remain uncertain, as the certainty of evidence for these analyses was low to very low, and future studies are likely to modify these conclusions.