Effect of dietary antioxidants, training and performance correlates on antioxidant status in competitive rowers.

The beneficial effects of exercise and a healthy diet are well documented in the general population, but poorly understood in elite athletes. Previous research in sub-elite athletes suggest regular training and an antioxidant-rich diet enhances antioxidant defences, but not performance.

PURPOSE:

To investigate whether habitual diet and/or exercise (training status or performance) affect antioxidant status in elite athletes.

METHODS:

Antioxidant blood biomarkers were assessed before and after a 30-min ergometer time trial in 28 males and 34 female rowers. The antioxidant blood biomarkers included ascorbic acid, uric acid, total antioxidant capacity (TAC), erythrocyte- superoxide dismutase (SOD), glutathione peroxidise (GPx) and catalase (CAT). Rowers completed a 7-d food diary and an antioxidant intake questionnaire. Effects of diet, training and performance on resting biomarkers were assessed with Pearson’s correlations and their effect on exercise-induced changes in blood biomarkers were assessed by a method of standardisation.

RESULTS:

With the exception of GPx, there were small to moderate increases with exercise for all markers. Blood resting TAC had a small correlation with total antioxidant intake (Correlation 0.29; 90% confidence limits, ±0.27) and the exercise-induced change in TAC had a trivial/small association with dietary antioxidant intake from -vitamin C (Standardised effect 0.19; ±0.22), -vegetables (0.20; ±0.23) and vitamin A (0.25; ±0.27). Most other dietary intakes had trivial associations with antioxidant biomarkers. Years of training had a small inverse correlation with TAC (-0.32; ±0.19) and a small association with the exercise-induced change in TAC (0.27; ±0.24).

CONCLUSION:

Training status correlates more strongly with antioxidant status than diet.