ALPHA-TOCOPHEROL SUPPLEMENTATION IN RACING CYCLISTS DURING EXTREME ENDURANCE TRAINING

This study was undertaken to evaluate the effects of 5 months of alpha -tocopherol supplementation on physical performance during aerobic exe rcise training in 30 top-class cyclists. Antioxidative effects of supp lementation were also studied. Plasma alpha-tocopherol concentration i ncreased significantly in the vitamin E-supplemented group, whereas th e placebo group showed a trend toward decrease. Physical performance d id not improve in the alpha-tocopherol-supplemented group compared to the placebo group. Heart rates were also not significantly different. Lactate concentrations at the aerobic threshold and the anaerobic thre shold were identical. Thus, there was no performance improvement in th e alpha-tocopherol-supplemented group. However there was a significant reduction in CK in serum of the E-supplemented group. A trend toward decrease in GOT, GPT, and LDH was observed with alpha-tocopherol suppl ementation. Moreover, significantly reduced malondialdehyde serum leve ls were measured in the E-supplemented group. The findings indicate a protective effect of alpha-tocopherol supplementation against oxidativ e stress induced by strenuous exercise.