In a recent study Acquilo et al. (Acquilo. 2010) have supplemented 18 amateur trained male athletes randomly with placebo or a mix of antioxidants (vitamin E, 500 mg/d; vitamin C, 1 g/d; and b-carotene, 30 mg/d) in the course of their usual training and competition season. The scientists found that
Other than it had been suggested in other studies it is quite evident from these findings that the supplement helped the athletes to avoid training induced negative endocrine changes and is thus likely to have ergogenic (at least anti-catabolic) effects.
Exercise decreased antioxidant defenses in the placebo group but not in the antioxidant-supplemented group. No changes were found in the number of erythrocytes, hematocrit, or hemoglobin concentration, or in values of serum iron parameters, after taking the antioxidant cocktail for 3 months, in spite of the exercise completed. The placebo group showed a high oxidative stress index, and decreases in serum iron (24%) and iron saturation index (28%), which can neither be attributed to aspects of the athletes' usual diet, nor to hemoconcentration.