Based on the above idea, a number of investigators have tested the hypothesis
that selenium supplements may be benef~cial in the attenuation of exercise-
induced oxidative stress. Olinescu et al.9 and Tessier et al.10,11 have reported
that selenium supplementation can be associated with a reduction in oxidative
stress in athletes. Both groups suggested that the reduction in oxidative
stress was secondary to a supplement-induced increase in blood and muscle
GSHPx activity. Although the above studies are intriguing, it is important
to note that other investigators have not been able to document an increased
need for selenium in athletes.12
It is significant to note that the increase in GSHPx activity noted following
selenium supplementation was not observed by Rokitzki et al.,13 when they provided vitamin E and C supplementation to trained athletes. Thus, the rise in GSHPx activity reported in the selenium supplementation studies may not occur if antioxidant supplements lacking selenium are provided.
Similar to the case for selenium, several investigators have suggested that
supplementation of zinc, copper, and/or magnesium may be of benefit to the
athlete with respect to the attenuation of exercise-induced tissue
oxidative damage.14 These theories will be briefly reviewed.
References
1. Consolazio et al., 1964.
2. Singh et al., 1991.
3. Ji LL. Oxidative stress during exercise: implication of antioxidant nutrients. Free Radic Biol Med 1995; 18: 1079-86.
4. Kanter MM. Free radicals, exercise, and antioxidant supplementation. J Sport Nutr 1994;4:205-20.
5. Sen CK. Oxidants and antioxidants in exercise. J Appl Physiol 1995;79:675-86.
6. Tidus PM, Houston ME. Vitamin E status and response to exercise training. Sports Med 1995;20: 12-23.
7. Leeuwenburgh C, Fiebig R. Chandwaney R. Ji LL. Aging and exercise training in skeletal muscle: responses of glutathione and antioxidant enzyme systems. Am J Physiol 1994;267 R439-45.
8. Pereira B. Costa Rosa LF, Safi DA, Medeiros MH, Curi R. Bechara EJ. Superoxide dismutase, catalase, and glutathione peroxidase activities in muscle and Iymphoid organs of sedentary and exercise-trained rats. Physiol Behav 1994;56:1095-9.
9. Olinescu R.Talaban D, Nita S. Mihaescu G. Comparative study of the presence of oxidative stress in sportsmen in competition and aged people, as well as the preventive effect of selenium administration. Rom J Int. Med 1995;33: 47-54.
10. Tessier F. Hilda H, Favier A, Marconnet P. Muscle GSHPx activity after prolonged exercise, training and selenium supplementation. Biol. Trace Elem Res 1995;47:279-85.
11. Tessier F. Margaritis I, Richard MJ, Moynot C., Marconnet P. Selenium and training effects on the glutathione system and aerobic performance. Med Sci Sports Exerc 1995;27:390-6.
12. Clarkson PM, Haymes EM. Trace mineral requirements for athletes. Int J Sports Nutr 1994;4:140-19.
13. Rokitzki L, Logemann E, Sagredos, et. Al Lipid peroxidation and antioxidative vitamins under extreme endurance stress. Acta Physiol Scand 1994; 151: 149-58.
14. Keen CL. Effects of exercise and heat on mineral metabolism and requirements. In: Marriot BM, ed. Nutritional Needs in hot environments. Washington, DC: National Academy Press, 1993. p. 1117-35.
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