Scientific researches about an oxidative stress are getting more and more popular among scientists. The oxidative stress occurs when there is a loss of balance between the production of free radicals (reactive forms of oxygen and nitrogen) and antioxidative protective mechanism (that neutralizes reactive forms of oxygen and nitrogen).
Intensification of oxygen consumption and intensified tempo of oxidative phosphorylation during constant physical effort causes the creation of free radicals of mitochondrial level. It leads to disorders in metabolic process and to the intensification of the process damaging a lot of cells structures. But, what is interesting, it has been proved that regular physical activity promotes strengthening of antioxidative organism protection.
In one research made by a team of scientists from Greece , the influence of ultra- long swimming on 50+/- 15 km (the average time of effort was 19,5 +/- 3,5 hours) on the level of oxidative stress among young competitors was examined. In this research 5 men aged about 28+ /- 6 took place in the research. The research compared the changes of oxidative stress level in blood. To do this, a sample of vein blood were taken immediately before and after the effort.
The results showed that, because of ultra-long swimming effort no intensification of oxidative stress in blood plasma was observed.
The authors claim that the results of the research done showed clearly that ultra- long swimming effort with a moderate intensity does not intensify the process of free radicals in well- trained sportsmen, that may confirm a sufficient anti- oxidative protection among well- trained sportspersons.
Kabasakalis A, Kyparos A, Tsalis G, Loupos D, Pavlidou A, Kouretas D. Blood oxidative stress markers after ultramarathon swimming. J Strength Cond Res, 2011; 25: 805-11.