The Effect of Exercise on Muscle Dysfunction in Cystinosis

Classification of activity tolerance is of importance in chronic progressive myopathies, not only to better understand functional implications of the disease state itself, but also for purposes of exercise prescription for health maintenance. Maximal exercise testing has been considered as the gold standard of assessing maximal aerobic capacity, however testing in individuals with neuromuscular disease is often limited due to pain, activity intolerance, musculoskeletal impairments, fatigue and other such related variables. Often, submaximal exercise testing can overcome some of these obstacles, and as such, is used frequently in the clinical environment. Non-ambulatory exercise testing utilizing an arm ergometer specifically has not been studied as heavily, especially in those with progressive myopathies. For this study, we will use maximal aerobic capacity testing for individuals with Cystinosis Myopathy utilizing a bike ergometer to allow testing of individuals regardless of their ambulatory status.