Exertional Muscle Pain Syndrome (EMPS) refers to myalgia primarily associated with exercise. Sometimes the cause can be identified but many cases are idiopathic.
Inherited causes:
(1) McArdle’s disease or other glycolytic disorder (myalgia triggered by high frequency and forceful muscle contractions that require anaerobic glycolysis)
(2) carnitine palmityl transferase (CPT) deficiency or other lipid storage myopathy (myalgia triggered by prolonged steady-state exercise that require fatty acid metabolism)