Effects of 8 weeks' endurance training on skeletal muscle metabolism in 56-70-year-old sedentary men.

The effects of 8 weeks' endurance training on muscle metabolism at rest and after a submaximal bicycle ergometer exercise were studied in 31 previously sedentary men, aged 56-70. Training consisted of 3-5 one hour exercise bouts per week including walking-jogging, swimming, gymnastics and ball games. The effects of training were similar to those previously reported for younger men. Mean maximal oxygen uptake increased (11%), as did the resting values for muscle glycogen concentration, the enzymes representing aerobic energy metabolism (malate dehydrogenase, succinate dehydrogenase), and also some of the anaerobic enzymes (creatine phosphokinase, lactate dehydrogenase). Lactate production during submaximal work decreased. The enzyme activities were lower following acute exercise both before and after training.