Physical Exercise in Myasthenia Gravis: A Systematic Review

Background: Myasthenia gravis (MG) is a chronic autoimmune disorder characterized by fluctuating skeletal muscle weakness and fatigue, leading to reduced functional independence and impaired quality of life (QoL). Although exercise has historically been discouraged due to concerns about symptom exacerbation, emerging evidence suggest that structured exercise programs may be safe and beneficial in clinically stable patients. This systematic review critically evaluates current evidence on exercise and physical activity interventions in MG, focusing on effectiveness, safety, and impact on functional outcomes, fatigue, and QoL. Materials and Methods: A systematic review was conducted following PRISMA guidelines. Searches were performed in PubMed, Web of Science, Google Scholar, Scopus and ScienceDirect for studies published between 2015 and 2025. Keywords included MG, physical activity, aerobic training, resistance training, and respiratory muscle training. Methodological quality was assessed using the Downs and Black checklist. Results: Eight controlled studies met the inclusion criteria, encompassing aerobic, resistance, combined, and respiratory muscle training interventions. Sample sizes ranged from small pilot studies to moderate-size randomized controlled trials. Overall, exercise interventions were well tolerated, with no evidence of sustained symptoms exacerbation. Aerobic and combined programs consistently improved functional capacity, muscle strength, and activities of daily living. Respiratory muscle training demonstrated improvements in pulmonary function and inspiratory muscle strength, although findings were more heterogeneous. Study quality ranged from poor to excellent, with common limitations including small sample size, short follow-up duration, and heterogeneity in exercise programs. Conclusions: Current evidence supports the safety and potential efficacy of individualized, symptom-guided exercise interventions in clinically stable MG. Regular physical activity exercise may reduce secondary deconditioning, improve functional outcomes, and enhance QoL. However, larger, high-quality randomized controlled trials with standardized programs and longer follow-up periods are required to strengthen clinical recommendations and clarify long-term effects.