LIPID-PEROXIDATION AND ANTIOXIDATIVE VITAMINS UNDER EXTREME ENDURANCESTRESS

The aim of this study was to examine whether extreme endurance stress of trained athletes can influence lipid peroxidation and muscle enzyme s. A randomized and placebo-controlled study was carried out on 24 tra ined long-distance runners who were substituted with alpha-tocopherol (400 I.U. d(-1)) and ascorbic acid (200 mg d(-1)) during 4.5 weeks pri or to a marathon race. The serum concentrations of retinol, ascorbic a cid, beta-carotene, alpha-tocopherol, malondialdehyde (TBARS) and uric acid as well as gluthation peroxidase (GSH Px) and catalase were meas ured 4.5 weeks before (A), immediately before (B), immediately after ( C) and 24 h after (D) the course. After competition (C) TBARS serum co ncentrations of the athletes (n = 22) decreased in both groups (P < 0. 0001). The ascorbic acid serum concentration increased significantly i n the supplemented group from (A) to (B) (P < 0.01), from (B) to (C) ( P < 0.001) and in the placebo group a significant increase from (B) to (C) (P < 0.01) was observed. The a-tocopherol serum concentration inc reased significantly in the supplemented group from (A) to (B) (P < 0. 001) and from (B) to (C) (P < 0.05). The enzymes glutathione peroxidas e (GSH Px) and catalase measured in erythrocytes as well as the serum selenium levels did not show significant differences at any time. A si gnificant increase of CK concentration was observed from (C) to (D) in the supplemented group (P < 0.01) and in the placebo group (P < 0.001 ). The increase of CK serum concentration is remarkably lower in the s upplemented group compared with the placebo group (P < 0.01). It is co ncluded that endurance training coupled with antioxidant vitamin suppl ementation reduces blood CK increase under exercise stress.