Metabolic myopathies are a group of inherited muscle disorders caused by defects in the body's ability to convert food into energy. These conditions affect how muscles use carbohydrates, fats, and proteins, leading to muscle weakness, cramps, and fatigue, especially during exercise. Common types of metabolic myopathies include glycogen storage diseases and fatty acid oxidation disorders. Diagnosis often involves blood tests, muscle biopsies, and genetic testing. Treatment focuses on managing symptoms and may include dietary changes, exercise programs, and sometimes medications to improve energy metabolism.