Comparative study of the presence of oxidative stress in sportsmen in competition and aged people, as well as the preventive effect of selenium administration.

The study demonstrates the presence of oxidative stress (OS) in physiological conditions in sportsmen in competition and in elderly subjects over 65 years. The OS was estimated by measuring some biochemical parameters, such as peroxides, total antioxidants, uric acid and free SH groups in plasma and peroxides in urine. OS produces a significant increase of peroxides in plasma and urine and a decrease of plasma antioxidants and SH groups. The presence of OS suggests an increased formation of free radicals in young subjects in sporting competition, This increase is subsequently compensated by an increase of antioxidants. In old agers, this unbalance remains unchanged. The level of OS is higher in sportsmen during competition, but the subsequent compensation depends on the degree of training, individual adaptation, diet, etc. The administration of organic selenium partially compensates and decreases the intensity of OS. This study confirmed the hypothesis that in old agers the formation of free radicals increases in the ageing process and recommends the prevention of OS in young sportsmen by an adequate protection with antioxidants, such as organic selenium.