Changes in muscle lipid metabolism with endurance training in man

Abstract

Eight men were studied before and after an endurance training program to assess changes in the lipid metabolism of skeletal muscle. Training consisted of eight weeks of outdoor running with daily mileage increasing from one-half mile at the onset to four miles at the eighth veekof training. In vitro analyses of palmityl-CoA oxidation and the activities of carnitine palmityltransferase (CPT) and succinate dehydrogenase (SDH) were observed in muscle samples obtained by needle biopsy from the gastrocnemius before and after training.The subjects' maximal oxygen uptake increased from 3.47 1/min (± 0.26) to 3.82 1/min (± 0.21) as a result of the training. At the same time, muscle CPT and SDH increased (P <.01) 23% and 36%, respectively. The muscle's capacity to oxidize palmityl-CoA increased from 6.36 nmoles/min/g to 13.32 nmoles/min/g, a significant increase of 116% (P <.01).This investigation supports earlier findings with rats and emphasizes the influence of chronic endurance exercise on lipid metabolism in the skeletal muscle of man.Ball State UniversityMuncie, IN 47306