Skeletal muscle metabolism during exercise in humans

Abstract

1. Contracting skeletal muscle is able to use a number of intra- and extramuscular substrates to generate ATP during exercise. These include creatine phosphate (CP), muscle glycogen, blood-borne glucose, lactate and free fatty acids (FFA), derived from either adipose tissue or intramuscular triglyceride stores. 2. During high-intensity short-duration exercise, CP degradation and the breakdown of muscle glycogen to lactate are the major energy yielding pathways, although oxidative metabolism can make a significant contribution. The 'anaerobic' substrates are also important fuels during the transition from rest to steady state exercise. 3. The oxidative metabolism of carbohydrate and lipid sup..