What are Antioxidants?
Before going into what antioxidants are, it is necessary to know what an oxidant is. Free radicals are unstable and very reactive molecules that steal electrons from other molecules (oxidation). This process results in the formation of more free radicals. Without an antioxidant to stop this chain reaction, it could continue to the point that all molecules have been oxidised. Oxidation can cause cell death, which can lead to many diseases and reductions in exercise performance. More information can be found in our "Antioxidants & Bodybuilding" article. Antioxidants can help to reduce cell damage, and hence speed up recovery and provide other beneficial effects for general health
There are many types of antioxidants, some of which are vitamins and vitamin-like substances (such as vitamin C, vitamin E, and coenzyme Q10), flavonoids, various enzymes within your body (catalase, superoxide dismutase, etc.), and other naturally occurring compounds.
Where do Antioxidants Come From?
Different antioxidants come from a variety of different natural sources. Plants such as acai, cranberries, spirulina, persimmons, bilberries, green tea, dandelion, soy, beetroot, and milk thistle, just to name a few, are all high in antioxidants.
Although there are many different forms of antioxidants, some of which are chemically unique, there are some general benefits of antioxidants.
Antioxidant Benefits for Recovery
Free radicals are produced by the body just from day to day life. However, this amount increases dramatically during exercise because of increased oxygen consumption. This could cause an overload of free radicals that the body may not be able to handle, leading to oxidative stress (Urso & Clarkson, 2003) and cell damage. It is thought that supplementing with antioxidants may be able to reduce the damage caused by exercise induced oxidative stress.
Specific antioxidants on their own and in combination with other antioxidants have been studied extensively by nutritionists and exercise scientists. The results of such studies are mixed and opinions vary, even among the experts. But there is evidence to suggest that antioxidant supplements are beneficial for athletes and bodybuilders. In some studies, when given a cocktail of antioxidants, it was found that subjects experienced reduced amounts of inflammation and markers of oxidative stress compared to those receiving a placebo (Vassilakopoulos et al, 2003; Fischer et al, 2004). Results such as this give evidence to suggest that recovery may be more rapid from reduced muscle damage from antioxidant supplementation.
Antioxidant Benefits for Health
The effects of antioxidants have been well studied in non-exercise related fields. One noteworthy study was conducted on over 13,000 French individuals over 7.5 years. The results showed that supplementation with low doses of antioxidants lowered incidences of cancer and general death in men (Hercberg et al, 2004)
Antioxidant Negatives and Side Effects
The other side of the antioxidant debate for exercise is that using antioxidant supplements reduces the body's ability to naturally build up a tolerance to oxidative damage (Ristow et al, 2009). Consequently, it has been said that the effects of antioxidants work best for non-trained individuals (Bloomer 2007), that is, those that have not yet naturally developed their own internal antioxidant defence system.
Because antioxidants are not a single compound, safety and side effects cannot be universally applied across every antioxidant. However, these compounds are generally considered to be safe if consumed at sensible doses.
Antioxidant Recommended Doses and Ingredient Timing
Again, because of the various forms of antioxidants, it is not possible to give a recommendation on dosage that applies across the board. For more information, please refer to specific articles (eg. vitamin C & vitamin E), and follow directions recommended by the manufacturer. This is also true for ingredient timing. However, many antioxidants can be taken with food throughout the day.
Antioxidants can be found as specific antioxidant supplements. Because of their potential mechanism for protecting against exercise induced oxidation, they are common in pre workout supplements and post workout supplements. Antioxidants also occur in a wide range of other supplements including multivitamins, protein powders, protein bars and much much more. When looking for antioxidants, remember to look for the specific type of antioxidant on the label (eg. vitamins C or E). It is very unlikely for a manufacturer to list "antioxidant" as an ingredient.
Antioxidants can be stacked with pretty much anything. Antioxidants can even be stacked with other antioxidants. In fact, this may be most effective way to benefit from antioxidants (Peake et al, 2006).
Bloomer (2007), The Role of Nutritional Supplements in the Prevention and Treatment of Resistance Exercise-Induced Skeletal Muscle Injury. Sports Medicine, 37: 519-532
Fischer et al (2004), Vitamin C and E supplementation inhibits the release of interleukin-6 from contracting human skeletal muscle. J Physiol, 558: 633-645
Hercberg et al (2004) The SU.VI.MAX Study A Randomized, Placebo-Controlled Trial of the Health Effects of Antioxidant Vitamins and Minerals. Arch Intern Med, 164: 2335-2342
Peake et al (2006), The influence of antioxidant supplementation on markers of inflammation and the relationship to oxidative stress after exercise. Journal of Nutritional Biochemistry, 18: 357-371
Ristow et al (2009), Antioxidants prevent health-promoting effects of physical exercise in humans. PNAS, 106: 8665-8670
Urso & Clarkson (2003), Oxidative stress, exercise, and antioxidant supplementation. Toxicology, 189: 41-54
Vassilakopoulos et al (2003). Antioxidants attenuate the plasma cytokine response to exercise in humans. J Appl Physiol, 94: 1025-1032