Balancing Precise and Safe Exercise in Myasthenia Gravis with Low Cardiorespiratory Endurance, Chest Expansion Limitation, and Obesity

Veronika Renny Kurniawati¹, Clarissa¹, Tresia Fransiska Ulianna Tambunan²

¹ Physical Medicine and Rehabilitation Department, Faculty of Medicine Universitas Indonesia, Cipto Mangunkusumo Hospital, Indonesia

² Physical Medicine and Rehabilitation Department, Faculty of Medicine Universitas Indonesia, Cipto Mangunkusumo Hospital, Indonesia

Korespondensi: Jalan Pangeran Diponegoro no. 71 Jakarta Pusat, telp. 087857355235, email: veronikarennykurniawati@gmail.com

Abstract

Introduction: Myasthenia gravis is an autoimmune disorder affecting the neuromuscular junction, characterized by fluctuating muscle weakness and fatigability. Exercise is considered safe in mild to moderate disease; however, prescription must be individualized, particularly in patients with cardiorespiratory limitations and obesity. Case Illustration: A 38-year-old woman with myasthenia gravis presented with fatigue during activities of daily living. She had a history of myasthenic crisis, mechanical ventilation, and thymectomy. At evaluation, she demonstrated class II obesity (BMI 36.5 kg/m²), reduced exercise capacity (6MWT 285 m; 3.49 METs), limited chest expansion, and mixed obstructive–restrictive ventilatory impairment. A structured pulmonary and physical rehabilitation program was initiated, including breathing exercises, chest mobility training, and aerobic exercise (40–50% HRR), along with energy conservation strategies. Discussion: Fatigue was predominantly peripheral, related to impaired neuromuscular transmission. Pulmonary dysfunction was multifactorial, involving respiratory muscle weakness, obesity-related restriction, and airway limitation. Following two weeks of rehabilitation, objective improvements were observed, including increased peak cough flow (PCF) (210→230 L/min), peak expiratory flow rate (PEF) (190→270 L/min), and single-breath count (SBCT) (37→45), along with improved chest expansion. These findings reflect enhanced ventilation, airway clearance, and respiratory muscle performance. Conclusion: Individualized exercise prescription, combined with respiratory rehabilitation, is safe and effective in myasthenia gravis with cardiorespiratory limitation. Comprehensive management, including obesity intervention, is essential to optimize functional outcomes and quality of life.

Keywords: Myasthenia Gravis, Exercise Tolerance, Obesity