Generalized fatigue in myasthenia gravis results in a sedentary lifestyle and profound physical deconditioning, leading to reduced fitness and increased risk of obesity, hypertension, dyslipidemia, and type 2 diabetes. This study will characterize the activity and fitness levels and cardiovascular disease risk profile in 30 chronic, generalized myasthenic subjects. Hypotheses are that a) subjects with myasthenia gravis are physically inactive with reduced fitness level and high incidence of obesity and poor cardiovascular disease risk profile, and b) a 3 month multi-modal home exercise program that includes aerobic, resistive, and pulmonary training components will improve physical activity, strength, fitness, dyspnea, body composition and reduce cardiovascular disease risk. Specific aims are to a) define the baseline physical activity and fitness levels and prevalence of insulin resistance and dyslipidemia in stable sedentary myasthenic subjects, b) determine whether a 3 month moderate intensity home exercise program is safe and feasible in deconditioned, stable myasthenic subjects and c) whether a 3 month comprehensive home exercise program can enhance fitness, strength, and lung function to improve physical activity and reduce cardiovascular disease risk.