This study was undertaken to evaluate the effects of 5 months of α-tocopherol supplementation on physical performance during aerobic exercise training in 30 top-class cyclists. Antioxidative effects of supplementation were also studied. Plasma α-tocopherol concentration increased significantly in the vitamin E-supplemented group, whereas the placebo group showed a trend toward decrease. Physical performance did not improve in the α-tocopherol-supplemented group compared to the placebo group. Heart rates were also not significantly different. Lactate concentrations at the aerobic threshold and the anaerobic threshold were identical. Thus, there was no performance improvement in the α-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 α-tocopherol supplementation. Moreover, significantly reduced malondialdehyde serum levels were measured in the E-supplemented group. The findings indicate a protective effect of α-tocopherol supplementation against oxidative stress induced by strenuous exercise.
L. Rokitzki is with Herzzentrum Bad Krozingen. E. Logemann is with Institute of Forensic Medicine, University Hospital Freiburg i. Br. G. H über and J. Keul are with Medical University Hospital Department of Sport and Performance Medicine A Iben-Ludwigs University, Freiburg i. Br. E. Keck is with Analytical Department Hoffmann-La Roche, Basel. Direct correspondence to L. Rokitzki, Benedikt Kreutz Rehabilitationszentrum für Herz- und Kreislaufkranke e.V., Söcking 15, 79188 Bad Krozingen, Germany.