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As we get older, our bodies gradually lose their capacity to fight free radicals with antioxidants—including those free radicals that cause fatigue during exercise. Could antioxidant supplementation combat this effect of aging on endurance performance?
A study conducted by researchers at University of California, Los Angeles and published in the Journal of the International Society of Sports Nutrition provides intriguing evidence that antioxidant supplementation may actually be helpful to older endurance athletes. The subjects of the study were 16 male cyclists between the ages of 50 and 73 years who trained at least four hours per week. Half of the subjects were randomly assigned to take an antioxidant supplement daily for three weeks while the others were given a placebo. All of the subjects engaged in their normal training during the study and all underwent performance testing at the start of the study, again after one week, and one last time after three weeks.
At week one, the subjects receiving the antioxidant supplement exhibited a 16.7 percent increase in anaerobic threshold. This increase was almost completely maintained at three weeks. There was no change in anaerobic threshold in the control group. The supplemented subjects also exhibited an increase in power output at anaerobic threshold while the control subjects did not.
It’s unclear how that increase was achieved. There were no major changes in any of the physiological parameters measured in the supplemented group. And a complicating factor is that the supplement used in this study contained the amino acid L-arginine in addition to antioxidant nutrients. L-arginine is known to increase the body’s production of nitric oxide, which helps the blood vessels relax, increasing blood flow. It is possible that this mechanism was responsible for the supplement’s effect on anaerobic threshold.
So, while the results of this study hint at the possible benefits antioxidant supplementation may offer aging athletes, more research is still needed. Stay tuned.