The effects of resistance training on myostatin and follistatin in adults: A systematic review and meta-analysis

Introduction and aim: Myostatin and follistatin are the main hormones for regulating muscle mass, and previous research suggests they are modulated by resistance training. We therefore performed a systematic review and meta-analysis to investigate the impact of resistance training on circulating myostatin and follistatin in adults. Methods: A search was conducted in PubMed and Web of science from inception until October 2022 to identify original studies investigating the effects of resistance training compared with controls that did not exercise. Standardized mean differences and 95% confidence intervals (CIs) were calculated using random effects models. Results: A total 26 randomized studies, including 36 interventions, and involving 768 participants (aged similar to 18 - 82 years), were included in the meta-analysis. Resistance training effectively decreased myostatin [-1.31 (95% CI-1.74 -0.88, p = 0.001, 26 studies] and increased follistatin [2.04 (95% CI: 1.51 - 2.52), p = 0.001, 14 studies]. Subgroup analyses revealed a significant decrease in myostatin and increase in follistatin regardless of age. Conclusion: Resistance training in adults is effective for reducing myostatin and increasing follistatin which may contribute to the beneficial effects of resistance training on muscle mass and metabolic outcomes.