Antioxidants for Sports & Fitness
Antioxidants are nutrients that help minimize free-radical damage to the body. Free radicals are highly reactive compounds that are created in the body during normal metabolic functions or introduced from the environment, such as by exposure to pollution and other toxins. Inherently unstable, free radicals contain “extra” energy which they try to reduce by reacting with certain chemicals in the body, which interferes with the cells’ ability to function normally. Antioxidants combat free radicals in several ways: they may reduce the energy of the free radical, stop the free radical from forming in the first place, or interrupt an oxidizing chain reaction to minimize the damage caused by free radicals.
ANTIOXIDANTS
Consuming a wide variety of antioxidant enzymes, vitamins, minerals, and herbs may be the best way to provide the body with the most complete protection against free-radical damage.
- The body produces several antioxidant enzymes, including superoxide dismutase, catalase, and glutathione peroxidase, that neutralize many types of free radicals. Supplements of these enzymes are available for oral administration. However, their absorption is probably minimal at best. Supplementing with the “building blocks” the body requires to make superoxide dismutase, catalase, and glutathione peroxidase may be more effective. These building block nutrients include the minerals manganese, zinc, and copper for superoxide dismutase and selenium for glutathione peroxidase.
- In addition to enzymes, many vitamins and minerals act as antioxidants in their own right, such as vitamin C, vitamin E, beta-carotene, lutein, lycopene, vitamin B2, coenzyme Q10, and cysteine (an amino acid). Herbs, such as bilberry, turmeric (curcumin), grape seed or pine bark extracts, and ginkgo can also provide powerful antioxidant protection for the body.
- An increasing number of antioxidant-rich "superfoods" are available, including mangosteen, kombucha, açaĂ, pomegranate, goji berry, and chia seed.
FREE RADICALS
Free radicals are believed to play a role in more than sixty different health conditions, including the aging process, cancer, and atherosclerosis.1 Reducing exposure to free radicals and increasing intake of antioxidant nutrients has the potential to reduce the risk of free radical-related health problems.
Oxygen, although essential to life, is the source of the potentially damaging free radicals. Free radicals are also found in the environment. Environmental sources of free radicals include exposure to ionizing radiation (from industry, sun exposure, cosmic rays, and medical X-rays), ozone and nitrous oxide (primarily from automobile exhaust), heavy metals (such as mercury, cadmium, and lead), cigarette smoke (both active and passive), alcohol, unsaturated fat, and other chemicals and compounds from food, water, and air.
Why Do Athletes Use It?*
Some athletes say that antioxidants help protect the body from free radicals.
What Do the Advocates Say?*
Antioxidants such as vitamin C, vitamin E, CoQ10, glutathione, and alpha lipoic acid are important supplements for everyone, but especially for those who exercise on a regular basis. The rationale is that exercise is a highly oxidative process and, as a consequence, produces free radicals from aerobic metabolism. Antioxidant compounds help alleviate this process.
There is conflicting evidence whether the best time to supplement with an antioxidant is before or after a workout.
How Much Is Usually Taken by Athletes?
Most research has demonstrated that strenuous exercise increases production of harmful substances called free radicals, which can damage muscle tissue and result in inflammation and muscle soreness. Exercising in cities or smoggy areas also increases exposure to free radicals. Antioxidants, including vitamin C and vitamin E, neutralize free radicals before they can damage the body, so antioxidants may aid in exercise recovery. Regular exercise increases the efficiency of the antioxidant defense system, potentially reducing the amount of supplemental antioxidants that might otherwise be needed for protection. However, at least theoretically, supplements of antioxidant vitamins may be beneficial for older or untrained people or athletes who are undertaking an especially vigorous training protocol or athletic event.2,3
Placebo-controlled research, some of it double-blind, has shown that taking 400 to 3,000 mg of vitamin C per day for several days before and after intense exercise may reduce pain and speed up muscle strength recovery.4,5,6 However, taking vitamin C only after such exercise was not effective in another double-blind study.7 While some research has reported that vitamin E supplementation in the amount of 800 to 1,200 IU per day reduces biochemical measures of free-radical activity and muscle damage caused by strenuous exercise,8,9,10 several studies have not found such benefits,11,12,13,14 and no research has investigated the effect of vitamin E on performance-related measures of strenuous exercise recovery. A combination of 90 mg per day of coenzyme Q10 and a very small amount of vitamin E did not produce any protective effects for marathon runners in one double-blind trial,15 while in another double-blind trial a combination of 50 mg per day of zinc and 3 mg per day of copper significantly reduced evidence of post-exercise free radical activity.16
In most well-controlled studies, exercise performance has not been shown to improve following supplementation with vitamin C, unless a deficiency exists, as might occur in athletes with unhealthy or irrational eating patterns.17,18 Similarly, vitamin E has not benefited exercise performance,19,20 except possibly at high altitudes.21,22