תזונה ותוספים Antioxidant Supplementation Does Not Alter Endurance Training Adaptation.

[Mike Bikov]

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Med Sci Sports Exerc. 2009 Dec 14. [Epub ahead of print]
Antioxidant Supplementation Does Not Alter Endurance Training Adaptation.

Yfanti C, Akerström T, Nielsen S, Nielsen AR, Mounier R, Mortensen OH, Lykkesfeldt J, Rose AJ, Fischer CP, Pedersen BK.

1Center of Inflammation and Metabolism at Department of Infectious Diseases, Rigshospitalet, University of Copenhagen, Denmark 2Institut Cochin, Université Paris Descartes, CNRS (UMR 8104), Paris, France; 3INSERM, U567, Paris, France 4Cellular and Metabolic Research Section, Department of Biomedical Sciences, University of Copenhagen, Denmark 5Section of Biomedicine, Department of Disease Biology, Faculty of Life Sciences, University of Copenhagen, Denmark. 6Molecular Physiology Group, Department of Exercise and Sport Sciences, Section of Human Physiology, University of Copenhagen, Denmark.

BACKGROUND:: There is a considerable commercial market, especially within the sports community, claiming the need for antioxidant supplementation. One argument for antioxidant supplementation in sports is that physical exercise is associated with increased reactive oxygen and nitrogen species (RONS) production, which may cause cell damage. However, RONS production may also activate redox sensitive signaling pathways and transcription factors, which subsequently may promote training adaptation. PURPOSE:: Our aim was to investigate the effects of combined vitamin C and E supplementation to healthy individuals on different measures of exercise performance after endurance training. METHODS:: Using a double-blinded placebo-controlled design, moderately trained young men received either oral supplementation with vitamins C and E (n=11) or placebo (n=10) before and during 12 weeks of supervised, strenuous bicycle exercise training of a frequency of 5 days/week. Muscle biopsies were obtained before and after training. RESULTS:: After the training period, maximal oxygen consumption, maximal power output, and workload at lactate threshold all increased markedly (P < .01) in both groups. Also, glycogen concentration, citrate synthase (CS), and beta-hydroxyacyl-CoA dehydrogenase (beta-HAD) activity in muscle were significantly higher in response to training (P < .01) in both groups. However, there were no differences between the two groups with regard to any of the physiological and metabolic variables measured. CONCLUSION:: Our results suggest that administration of vitamins C and E to individuals with no prior vitamin deficiencies has no effect on physical adaptations to strenuous endurance training.​

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