Abstract
BACKGROUND: Exercise, protein supplementation, and their combination are guideline-recommended strategies for managing sarcopenia. This study aimed to compare the effectiveness of various types of voluntary and simulated exercise on the outcomes of muscle strength, physical function, and muscle mass in individuals with sarcopenia. METHODS: We systematically searched PubMed, Embase, Web of Science, and the Cochrane Central Register of Controlled Trials through December 2024 and conducted a frequentist random-effects network meta-analysis. The certainty of evidence was assessed using the GRADE framework, and interventions were categorized according to their relative effectiveness and certainty ratings. RESULTS: A total of 96 eligible studies involving 7,596 participants were included. Resistance and balance training combined with protein-based nutritional supplementation (RBT + Nu) was the most effective intervention for improving grip strength (MD = 5.45 kg, 95% CI: 3.58-7.33), gait speed (MD = 0.20 m/s, 95% CI: 0.11 to 0.29), SPPB (MD = 3.59 points, 95% CI: 1.91-5.27), and skeletal muscle index (MD = 0.95 kg/m², 95% CI: 0.16-1.74). Improvements in gait speed and SPPB exceeded the minimal clinically important difference, while gains in grip strength were potentially clinically meaningful. Resistance and balance training (RBT) achieved the most significant improvement in the timed up and go test (MD = -2.29 s, 95% CI: -3.16 to -1.41), whereas aerobic and resistance training combined with nutrition was most effective in the five-times sit-to-stand test (MD = -2.86 s, 95% CI: -4.55 to -1.17); both improvements are potentially clinically meaningful. Resistance training with nutrition showed the largest improvements in knee extension strength (SMD = 0.98, 95% CI: 0.63-1.33) and appendicular skeletal muscle mass (MD = 0.33 kg/m², 95% CI: 0.27 to 0.38). Aerobic, resistance, and balance training produced the greatest benefit for balance performance (SMD = 0.73, 95% CI: 0.13-1.34). CONCLUSION: High-certainty evidence supports RBT + Nu as the most effective intervention for improving muscle strength, muscle mass, and physical function in individuals with sarcopenia. We recommend combining RBT with protein and amino acid supplementation as an optimal strategy when feasible.