Controversies exist as to the magnitude and direction of changes in serum lipid peroxides associated with exercise. For this reason, this study investigates the effects of short-term exhaustive exercise and moderate prolonged exercise on lipid peroxidation in a variety of subjects. In the exhaustive test a work rate was increased 15-22.5W every minute until the termination of exercise, while a work rate corresponding to anaerobic threshold was maintained for 1 or 2 hours in the prolonged test. Serum lipid peroxides remained essentially unchanged in obese women and male distance runners following one-hour exercise, and tended to decrease on a 2-hour run test in which other male distance runners were employed. However, significant increase in serum lipid peroxides was observed for both trained and untrained men immediately after the exhaustive exercise. One hour afterward, the value was at resting level. These results suggest that lipid peroxidation is accelerated in short-term exhaustive exercise where profound muscle hypoxia occurs. O₂⁻ produced by xanthine oxidase in uric acid metabolism may facilitate lipid peroxidation during exercise of high intensity. On the other hand, lipid peroxidation seems to be inhibited in an almost entirely aerobic condition.

DESCENTE SPORTS SCIENCE Vol.8/THE DESCENTE AND ISHIMOTO MEMORIAL FOUNDATION FOR THE PROMOTION SPORTS SCIENCE