Recently, antioxidants have received positive attention with respect to anti-aging. Studies have also demonstrated that anti-oxidants provide protection against a number of diseases such as cataracts, diabetes and many cancers. In the sports world, antioxidants have received interest due to the possibility antioxidants boost performance, encourage recovery and defend against free radicals. Since this article just skims the surface, read more about athletes and antioxidants here.
What are Free Radicals and Why Would I Care About Them?
Free radicals are chemical species with one or more unpaired electrons in their outer orbit that makes them highly reactive. Physical activity produces an increase in oxygen expenditure reflecting the muscle’s use of oxygen to provide energy in the form of ATP (adenosine triphosphate). As oxygen use rises so does the production of free radicals. There is apprehension that the boost in free radicals generated during strenuous exercise may exceed the body’s antioxidant defense system. To guard against this we propose athletes take antioxidant supplements.
Previously we have said that consistent physical exercise enhances the antioxidant defense system and protects against exercise induced free radical damage. Are we now saying that frequent physical exercise is damaging? No, the level of intensity and extent are what we should to pay attention to: Intense exercise, particularly in untrained persons, overrides the defense system resulting in increased free radical damage. Furthermore, endurance exercise increases oxygen utilization up to 20 times as much as the resting state. Increased oxygen utilization means an increase in the production of free radicals. The consequence is muscle and tissue damage.
Antioxidant supplementation was once supposed as being safe. However, there is growing indication of interactions and potential toxicity. For example, vitamin C and beta-carotene are considered antioxidants at ordinary concentrations, but at higher concentrations they become harmful substances called prooxidants.
Degree of conditioning of the athlete, intensity of exercise, and diet are therefore among the factors determining the degree of exercise induced free radical damage. This article centers on 1) how well athletes can protect against the increased free radicals ensuing from exercise and 2) whether antioxidant supplementation is necessary.
In general the idea that a well-nourished athlete should supplement with antioxidants is controversial. It is not feasible to precisely measure free radicals in the body. Most studies assess the by-products that result from free radical reactions. If the production of free radicals exceeds the body’s antioxidant defenses then we will be able to measure and detect the by-products of free radicals. The results of many studies are conflicting.
Other than vitamins C and E, which positively show protection against exercise induced oxidative damage, there is no clear scientific proof that most antioxidant supplements aid in defense against exercise induced oxidative damage. Vitamin E also demonstrated enhanced recovery following intense exercise.
For athletes adapting to high altitude training (such as skiing or mountaineering), vitamin E might be a useful supplement because it did demonstrate less free radical damage and a lesser drop in anaerobic threshold in one particular placebo-controlled review on mountaineers.
Recommendations for Athletes and Antioxidants
Antioxidant supplementation is sure to remain a debatable issue because of its hint of performance and health-enhancing roles. However, taking chemicals without a complete understanding of all of their effects may interrupt balance in our bodies. Until more definitive research data is available, the following are recommendations for those athletes considering supplementation:
* An athlete’s diet is capable of providing the necessary components for an inherent antioxidant system. Eating 5 servings of fruit or vegetables per day along with a steady exercise program will ensure this.
* Weekend warriors should keenly ponder a more balanced method to exercise. Failing that, consider supplementation but be sensitive to the fact that very little is known about the long term consequences of antioxidant supplementation.
* For extremely demanding races (endurance events such as Ironman), or when adapting to high altitude, contemplate taking a vitamin E supplement (100 to 200 IU, approximately 10 times the RDA) per day for several weeks up to and following the race.
* Continuously explore FDA recommendations, but be wary of advertising and media hype.
* Keep in mind that other than exercise-induced, free radicals can additionally be generated from smog and other environmental sources. Do not exercise in areas with considerable air pollution.