title: Beta endorphin: a factor in "fun run" collapse?
mesh_terms: D000328:Adult; D005221:Fatigue / Q000097:blood / Q000209:etiology*; D006801:Humans; D008297:Male; D012420:Running; D001615:beta-Endorphin / Q000097:blood*
chemical_list: D001615:beta-Endorphin