CHANGES IN PLASMA ANTIOXIDANT STATUS DURING ECCENTRIC EXERCISE AND THE EFFECT OF VITAMIN SUPPLEMENTATION

Twenty-four healthy students undertook one hour of box-stepping exerci se. Prior to exercise eight had received no medication (Group A), eigh t received 400 mg of vitamin C daily for three weeks before and one we ek after exercise (Group C) and eight received 400 mg of vitamin E for the same period (Group E). Groups C and E had significantly higher le vels of vitamin C (p < 0.01) and vitamin E (p < 0.01) respectively tha n group A at the commencement of exercise. Plasma total antioxidant ca pacity rose significantly during exercise in all groups (A - p < 0.05; C - p < 0.001; E - p < 0.001). This rise was accounted for by increas es in plasma uric acid in all groups. In addition there were significa nt increases in vitamin C in group C (p < 0.001) and vitamin E in grou p E (p < 0.05). There were no significant changes in plasma malondiald ehyde following exercise in any group. li is concluded that plasma ant ioxidant capacity rises in response to one hour of eccentric exercise and that the contribution of individual antioxidants to this change ca n be influenced by vitamin supplementation. The possible mechanisms of the antioxidant changes during exercise and their implications are di scussed.