Effect of aerobic and anaerobic metabolism on free radical generation swimmers

In this study, changes in antioxidant systems due to free radicals were investigated in short distance (100-m) and long-distance (800-m) swimmers, within whom the anaerobic and aerobic metabolisms dominate, respectively. For this study, swimmers aged between 15 and -21 yr swam 800 m (N = 10) and 100 m (N = 9). Venous blood samples were taken before swimming, and at 1-, 20-, and 40-min intervals after swimming. Lactate, catalase (CAT), glutathione peroxidase (GPx), and reduced glutathione (GSH) levels were determined in the blood samples. The increase of lactate levels was statistically significant in the swimmers, both after the 100- and 800-m distances as compared with the preswimming levels (P < 0.001, P < 0.001). Catalase activity was increased in the first minute postswimming as compared with preswimming levels. Catalase activity then decreased at the 20- and 40-min intervals as compared with the 1-min postswimming interval, at both 100- and 800-m distances (P < 0.01, P < 0.001). GPx activity was also increased in the first minute after swimming as compared with preswimming levels. GPx activity then decreased at the 20- and 40-min intervals when compared with the 1-min postswimming level. This occurred in both 100- and 800-m swimmers (P < 0.001, P < 0.001). GSH activity was decreased in the first minute after swimming, compared with the preswimming levels. GSH activity then increased at the 20- and 40-min postswimming intervals, as compared with the first-minute level. Again, this occurred in both the 100- and 800-m swimmers (P < 0.001, P < 0.01). We concluded that both long-distance and particularly short-distance (100-m) swimming increased the activities of antioxidant defense enzymes.