The myopathies represent a diverse group of genetic and acquired disorders that negatively affect skeletal muscle structure and funciton. In general, these disorders lead to a reduction in strength and/or endurance. I will focus the current talk on two common forms of muscular dystrophies (myotonic MD type 1 (DM1)), fascio-scapulohumeral MD (FSHD)) and two metabolic disorders (Pompe disease, mitochondrial myopathy). Although the primary cause of each disorder is unique, weakness and/or exercise intolerance typically leads to a general reduction in energy expenditure that further constrains nutrient recommendations due to a lower energy intake required to maintain optimal body composition. Our recent data suggests that most myopathy patients have obesity with low lean mass (OLMM). We have also reported sub-optimal intake of most micronutrients in patients with several types of muscular dystrophy and also found low blood levels of vitamin D, vitamin B12, folate and vitamin E. We and others have found low levels of muscle creatine and phosphocreatine in several myopathies and multiple studies have shown that creatine monohydrate supplementation can increase muscle strength and mass by ~ 7 % in MD. Higher oxidative stress is seen in most myopathies and targeted anti-oxidant cocktails have shown benefits in mitochondrial myopathies, Pompe disease and FSHD. A higher protein intake (> 1.2 g/kg/d) is also recommended for myopathy patients, especially Pompe disease. We are currently evaluating whether supplementation with milk protein, creatine monohydrate, vitamin D, calcium and a multi-ingredient supplement will enhance the gains made from multi-modal exercise training in patients with DM1 and Pompe.