Rhabdomyolysis: Necrosis or disintegration of skeletal muscle often followed by myoglobinuria.MyoglobinuriaAcute Kidney Injury: Abrupt reduction in kidney function. Acute kidney injury encompasses the entire spectrum of the syndrome including acute kidney failure; ACUTE KIDNEY TUBULAR NECROSIS; and other less severe conditions.Creatine Kinase: A transferase that catalyzes formation of PHOSPHOCREATINE from ATP + CREATINE. The reaction stores ATP energy as phosphocreatine. Three cytoplasmic ISOENZYMES have been identified in human tissues: the MM type from SKELETAL MUSCLE, the MB type from myocardial tissue and the BB type from nervous tissue as well as a mitochondrial isoenzyme. Macro-creatine kinase refers to creatine kinase complexed with other serum proteins.Heat Exhaustion: A clinical syndrome caused by heat stress, such as over-exertion in a hot environment or excessive exposure to sun. It is characterized by SWEATING, water (volume) depletion, salt depletion, cool clammy skin, NAUSEA, and HEADACHE.Myoglobin: A conjugated protein which is the oxygen-transporting pigment of muscle. It is made up of one globin polypeptide chain and one heme group.Glycogen Storage Disease Type V: Glycogenosis due to muscle phosphorylase deficiency. Characterized by painful cramps following sustained exercise.Water Intoxication: A condition resulting from the excessive retention of water with sodium depletion.Muscular Diseases: Acquired, familial, and congenital disorders of SKELETAL MUSCLE and SMOOTH MUSCLE.