The effect of winter swimming on concentration of malondialdehyde in erythrocytes and blood plasma of healthy individuals – a preliminary report

Abstract

Introduction: Variable environmental conditions can disturb oxidant-antioxidant balance. The particular type of such changes in warm-blooded organisms is caused by sudden cooling. The organism tries to prevent the harmful effects of cold by activating many reactions leading to preserve homeostasis. Nevertheless, these mechanisms are often insufficient and oxidative stress occurs, which is manifested by increased lipid peroxidation. <br>Purpose of the study: The purpose of the study was to determine the effect of cold water immersion on the concentration of malondialdehyde (the main product of lipid peroxidation) in the blood of regular and novice winter swimmers. <br>Material and methods: The study was conducted in a group of 30 healthy volunteers, half of whom were regular winter swimmers and half were novices. All participants were exposed to low temperatures during a 3-minute bath in a river, water temperature was 0°C, while the ambient temperature was +4°C. Blood samples were taken three times: at baseline, as well as 5 and 30 minutes after cold water immersion. Concentrations of malondialdehyde (MDA) in both plasma and erythrocytes were determined. <br>Results: There were no statistically significant differences of plasma and erythrocytic MDA concentrations between regular winter swimmers and controls at baseline. The significant decrease in plasma MDA concentration (19.4%; p<0.05) was observed in regular winter swimmers 5 minutes after leaving the cold water. Likewise, a statistically significant decreases of MDA concentrations were observed in the erythrocytes of the regular winter swimmers, both 5 minutes (37,1%; p<0.05) and 30 minutes (33,4%; p<0.05) after winter swimming. There were no significant changes in MDA concentrations in both blood plasma and erythrocytes of controls due to exposure to low temperatures. Nevertheless, a trend to lower concentrations of these parameters were observed in this group of swimmers. <br>Conclusions: The decrease of MDA concentration in patients who regularly use cold water immersion and the trend to decrease this parameter in control group demonstrated in this paper may indicate a rapid and effective removal of lipid peroxidation products as a result of peripheral hyperemia. Furthermore, the results suggest that the mechanisms of defence against oxidative stress may be more effective in the regular winter swimmers than in people not regularly exposed to low temperatures. This may point to the activation of adaptive mechanisms as a result of regular cold water immersions.