Prooxidant-antioxidant equilibrium in rowers: effect of a single dose of vitamin E

The purpose of this research was to explain whether a single dose of vitamin E influences on disturbances of pro-oxidant-antioxidant equilibrium induced a laboratory 2,000 m rowing test.

The athletes were divided into two groups: vitamin E (1.000 mg alfa-tocopherol acetate) and P (placebo: cod-liver oil) supplemented 3 h before exercise. In the subjects' blood levels of following parameters were estimated: superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), lipid peroxidation products (TBARS) and protein carbonyls (PC). Creatine kinase (CK) and beta-glucuronidase (betaG) activities were also measured as markers of muscle damage.

The applied exercise at maximal intensity (lactate: vitamin E=14.39+/-1.77 mmol/L, P=14.09+/-1.4 mmol/L) caused significant changes in the tested parameters in both groups: SOD (vitamin E Ø30%, P Ø50%), CAT (vitamin 70%, P 12%), GPx (vitamin 49%, P 45%), TBARS (vitamin 70%, P 71%), PC (vitamin 41%, P 78%), CK (vitamin 19%, P 32%), betaG (vitamin 42%, P 47%). The P/A ratio (TBARS/SOD+CAT+GPx) was significantly lower in vitamin E in comparison with placebo, but after 30 min and 24 h restitution it returned to pre-exercise level. Between P/A ratio and PC concentration there was observed positive correlation (P<0.001). No effect of vitamin E on CK and betaG activities were observed.

A single dose of 1,000 mg vitamin E enhances oxidative defense thus attenuates oxidative damage but it is not so much relevant to recommend the antioxidant supplementation by rowers.