Endurance exercise and muscle damage: Relationship to lipid peroxidation and scavenging enzymes in short and long distance runners

Abstract

A study was conducted to investigate the effect of endurance exercise on plasma lipid peroxidation product and on the activity of scavenging enzymes in erythrocytes in short and long distance runners. The activity of scavenging enzymes [superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px)] in erythrocytes, plasma lipid peroxide level (malondialdehyde, MDA) and the activity of plasma lactate dehydrogenase (LDH) and creatine phosphokinase (CPK) were measured in resting condition. The subjects then exercised on a bicycle ergometer at 70% of maximum heart rate for 60 min. SOD, GSH-Px and CAT activities were significantly decreased by 34%, 23% and 20% (p < 0.001) respectively in sedentary subjects after endurance exercise. However, SOD and GSH-Px activities were not significantly changed in both short and long distance runners except a slight reduction in CAT activity was detected after endurance exercise. These results demonstrate that training in short and long distance runners increases the activity of the main free radical scavenging enzymes in erythrocytes and that the endurance exercise inactivates CAT only. Moreover, plasma lipid peroxide level and the activities of LDH and CPK were significantly increased in sedentary subjected after endurance exercise when compared with those in short and long distance runners. It is concluded that there is a degree of adaptation to training in short and long distance runners that might be effective in muscle damage protection after endurance exercise.