The importance of antioxidants for health and athletic performance
- The production of free radicals is increased during exercise and as a consequence of aging
- Antioxidants help to protect the body against free radicals that cause damage to cells and cell structures
- Benefits associated with antioxidant supplementation include
- promoting exercise performance and recovery,
- strengthening immune defence, and
- promoting health and protecting against several disease states
- Optimizing the body’s antioxidant status is best achieved through a combination of an antioxidant-rich diet and targeted supplement intake
Free radical production and antioxidant defences
Free radicals are highly reactive molecules that react with and damage other molecules in the body such as protein, fat and deoxyribonucleic acid (DNA) structures1, 2. On the other hand, antioxidants work like a defence mechanism to help to protect the body by “mopping-up” free radicals, therefore helping to reduce free radical damage. A process known as oxidative stress (damage to protein, fat, or DNA) occurs when the production of free radicals exceeds the body’s antioxidant defence system3.
During energy production in almost every cell in the body, oxygen molecules are reduced (broken down), meaning they lose an atom from their outer shell. However, the oxygen molecule is not always re-formed, which turns the oxygen molecule into a very potent “reactive oxygen species” (or ROS for short), which is also known as a free radical4. Exercise dramatically increases the rate of energy production and therefore the production of free radicals, increasing the potential for oxidative damage to occur5.
Types of antioxidants
There are two types of antioxidant defences: (i) endogenous antioxidants, which are made by or naturally-present in the body, and (ii) exogenous antioxidants, which are derived by dietary means and used by the body. The endogenous and exogenous antioxidants work together to help strengthen the body’s antioxidant defences and protect against oxidative damage. Some of the key exogenous antioxidants that are associated with numerous health- and performance-related benefits include Vitamin C, Vitamin E, carotenoids (-carotene, lutein and lycopene), coenzyme Q10 (CoQ10), ornithine alpha-ketoglutarate (AKG), arginine AKG and alpha-lipoic acid (ALA; which can also be derived from endogenous sources). These antioxidants are naturally-present in food, but are also available in concentrated supplemental form, which may be beneficial for athletes and individuals that train regularly who have increased antioxidant demands5.
Antioxidant requirements and status in the general population and athletes
An increase in free radical production and/or inadequate antioxidant defences leads to increased levels of oxidative stress. Exercise training enhances the body’s endogenous antioxidant defence system6, i.e. the body develops an ability to protect itself in the face of increased production of damaging molecules. However, this still may be insufficient to protect the body against the marked increased production of free radicals that occurs during exercise or periods of heavy training6. Furthermore, oxidative stress levels particularly increase during periods of unaccustomed exercise training (like when you start a new training phase or perform new exercises) 1, periods of high-volume training and competition demands7 or exercising at altitude8. Fortunately, antioxidant supplementation reduces exercise-induced oxidative damage1, 2, and therefore people who exercise regularly, and in particular at high intensities, are likely to benefit from antioxidant supplementation.
What does the research say?
Inadequate antioxidant defences have been shown to impair sports performance and recovery from exercise5, 9,10, while antioxidant supplementation enhances sports performance and recovery rates3, 11-14. Antioxidant supplementation has also been shown to enhance immune function6, 15-17, and protect the body against developing cataracts18 and several disease states including cardiovascular disease (CVD) 19, cancer20, diabetes21, multiple sclerosis22, muscular dystrophy23, Parkinson’s disease24 and arthritis25.
i. Sports performance and recovery from training
Inadequate antioxidant intake exacerbates exercise-induced oxidative stress levels26, which may speed up the rate of impaired muscle function, leading to the early onset of fatigue5, 9,14 and impaired exercise performance. Additionally, exercise-induced free radical production has also been shown to increase feelings of perceived exertion (tiredness) 26. Indeed, antioxidant deficiency and/or suboptimal antioxidant defences have been shown to decrease endurance capacity (by up to 40%), reducing exercise time to exhaustion5, 9, impair sprint performance10 and decrease muscular force (by 38%) 9. In contrast, daily antioxidant supplementation (with vitamin E and/or polyphenol-rich green tea extract (GTE) for 10 weeks) enhances endurance performance, increasing exercise time to exhaustion (by up to 32%) 11,12. Furthermore, antioxidant supplementation may be of particular importance to athletes during periods of unaccustomed exercise1, during in-season when training and competition demands are high4, while training at altitude8, and any other situations when the energy demands and oxidative stresses placed upon athletes are increased.
During recovery, damaged muscles attract immune cells that release free radicals27, which leads to further protein (muscle) damage. Antioxidant deficiency further increases susceptibility to oxidative (muscular) damage5, 14. However, supplementation with vitamin C (400mg/day for 2 weeks) and/or GTE (equivalent to 640mg polyphenols/day for 4 weeks) reduces the severity of exercise-induced muscle damage3 and muscle soreness levels13. These post-exercise recovery benefits associated with antioxidant supplementation may be due to a variety of different mechanisms including reduced levels of fat and protein damage14, which are important components of muscle structures; decreased levels of inflammation13; and/or reduced concentrations of markers associated with muscle damage3.
Daily antioxidant supplementation with vitamin C (152mg/day) and vitamin E (50mg/day) for one month has been shown to help strengthen immune defences6, which may help reduce potential training days lost due to illness. Oxidative stress increases the risk of damage to immune cells, consequently reducing immune status8. In contrast, antioxidant supplementation helps to maintain immune integrity following prolonged, intense exercise6 and may help to reduce susceptibility to upper respiratory tract infections (due to dampened immunity during the post-training period) 15. Furthermore, supplementation with luteolin (a flavanoid-rich compound), vitamin C, vitamin E and/or CoQ10 may also help to protect the body against exposure to environmental toxins such as ultraviolet rays16 and air pollutants17, which may be especially important for athletes training outdoors.
iii. Promoting health and protection against disease
Supplementing with antioxidants such as vitamin C, vitamin E and carotenoids increases the body’s total antioxidant capacity, providing increased protection against oxidative damage, which may decrease the risk of developing cataracts18 and help protect the body against numerous disease states including cardiovascular disease (CVD)19, cancer20, diabetes21, multiple sclerosis22, muscular dystrophy23, Parkinson’s disease24 and arthritis25.
What does this mean in practice?
Antioxidants are found in a variety of foods, the richest sources being plant sources including dark-coloured vegetables, citrus fruits, legumes, nuts, grains, seeds, oils, herbs and spices. However, due to the high training demands and consequent increased oxidative stresses imposed upon athletes6, 7, diet alone is unlikely to provide sufficient antioxidant support to protect the body against oxidative damage. To this end, consuming antioxidants in supplement form as an adjunct to a healthy, antioxidant-rich diet is likely to offer the following benefits:
- Endurance training: may help to reduce the perception of fatigue, enhancing performance
- Team-sport athletes: may help to enhance sports performance by maintaining muscular force and performance during exercise, and also speed up post-exercise recovery rates
- Gym-based training: may help to delay fatigue and maintain muscular force
- Recovery:may help to promote for more rapid recovery from training by limiting muscle damage, decreasing inflammation and reducing muscle soreness levels
- Illness: may help to strengthen immune defence, therefore reducing potential training days lost due to illness, a key consideration for elite athletes
- Health promotion and disease protection: supplementation may help to provide protection against environmental toxins and pollutants such as UV rays and air pollution; decrease the risk of developing cataracts; and protect against several disease states such as CVD, cancer, arthritis, multiple sclerosis, muscular dystrophy and Parkinson’s disease
Antioxidant supplementation at ROS Nutrition
ROS Nutrition provides a range of different antioxidant supplements, each one specially formulated to tailor to individual demands. Accovit® Daily is a balanced vitamin and mineral supplement, formulated to maintain optimum health. Similarly, Accovit® Performance is also a vitamin and mineral supplement, however it caters for the increased vitamin, mineral and antioxidant requirements of athletes and regularly exercising individuals. ALA 600 contains α-lipoic acid, a powerful water- and fat- soluble antioxidant, which helps to strengthen immunity and protect against disease. Coenzyme Q10 is a naturally-occurring vitamin-like substance that also has potent antioxidant action. Omniflex® is a specialized formula containing natural food extracts (ginger, curcumin, boswellia and green coffee) shown to have strong antioxidant potential, which is targeted to reduce inflammation and speed up post-exercise recovery rates. ProAct ZMA® contains ornithine AKG and arginine AKG, aimed to support muscle growth and improve muscle strength and power. Finally, ROS Nutrition’s specialized high-strength Vitamin C supplement aims to help protect against disease and strengthen the body’s immune defences.
Find antioxidants at ROS Nutrition
- Abadi A, Crane JD, Ogborn D, Hettinga B, Akhtar M, Stoki A, Macneil L, Safdar A & Tarnopolsky M (2013) Supplementation with α-lipoic acid, CoQ10 and vitamin E augments running performance and mitochondrial function in female mice. PLoS One, 8 (4), 1-12.
- Fogarty MC, Devito G, Hughes CM, Burke G, Brown JC, McEneny J, Brown D, McClean C & Davison GW (2013) Effects of α-lipoic acid on mtDNA damage after isolated muscle contractions. Med Sci Sports Exer, 45 (8), 1469-1477.
- Jówko E, Sacharuk J, Balasinska B, Ostaszewski P, Charmas M & Charmas R (2011) Green tea extract supplementation gives protection against exercise-induced oxidative damage in healthy men. Nutr Res, 31 (11), 813-821.
- Sjödin B, Westing YH & Apple FS (1990) Biochemical mechanisms for oxygen free radical formation during exercise. Sports Med, 10 (4), 236-254.
- Davies KJA, Quintanilha AT, Brooks GA & Packer L (1982) Free radicals and tissue damage produced by exercise. Biochem Biophys Res Comm, 107 (4), 1198-1205.
- Sureda A, Ferrer MD, Mestre A, Tur JA & Pons A (2013) Prevention of neutrophil protein oxidation with vitamins C and E diet supplementation without affecting the adaptive response to exercise. Int J Sport Nutr Exerc Metab, 23 (1), 31-39.
- Schröder H, Navarro E, Tramullas A, Mora J & Galiano D (2000) Nutrition antioxidant status and oxidative stress in professional basketball players: Effects of a three compound antioxidative supplement. Int J Sports Med, 21 (2), 146-150.
- Carrera-Quintanar L, Lopez-Fuertes M, Climent V, Herranz-Lopez M, Micol V, Pons A, Sogorb F & Roche E (2012) Oxidative damage is present in plasma and circulating neutrophils 4 weeks after a high mountain expedition. Eur J Appl Physiol, 112 (8), 2923-2932.
- Gohil K, Packer L, de Lumen B, Brooks GA & Terblanche SE (1986) Vitamin E deficiency and Vitamin C supplements: Exercise and mitochondrial oxidation. J Appl Physiol, 60 (6), 1986-1991.
- Groussard C, Machefer G, Rannou F, Faure H, Zouhal H, Sergent O, Chevanne M, Cillard J & Gratas-Delamarche A (2003) Physical fitness and plasma non-enzymatic antioxidant status at rest and after a wingate test. Can J Appl Physiol, 28 (1), 79-92.
- Murase T, Haramizu S, Shimotoyodome A, Nagasawa A & Tokimitsu I (2005) Green tea extract improves endurance capacity and increases muscle lipid oxidation in mice. Am J Physiol Regul Integr Comp Physiol, 288, R708-R715.
- Devi SA, Prathima S & Subramanyam (2003) Dietary vitamin E and physical exercise: Altered endurance capacity and plasma lipid profile in ageing rats. Exper Gerontol, 38 (3), 285-290.
- Thompson D, Williams C, McGregor SJ, Nicholas CW, McArdle F, Jackson MJ & Powell JR (2001) Prolonged vitamin C supplementation and recovery from demanding exercise. Int J Sport Nutr Exerc Metab, 11 (4), 466-481.
- Coombes JS, Rowell B, Dodd SL, Demirel HA, Naito H, Shanely AR & Powers SK (2002) Effects of vitamin E deficiency on fatigue and muscle contractile properties. Eur J Appl Physiol, 87 (3), 272-277.
- Peters EM, Goetzsche JM, Grobbelaar B & Noakes TD (1993) Vitamin C supplementation reduces the incidence of postrace symptoms of upper-respiratory-tract infection in ultramarathon runners. Am J Clin Nutr, 57, 170-174.
- Su HJ, Chang CH & Chen HL (2013) Effects of vitamin C and E intake on peak expiratory flow rate of asthamatic children exposed to atmospheric particulate matter. Arch Environ Occup Health, 68 (2), 80-86.
- Jacques PF & Chylack LT (1991) Epidemiologic evidence of a role for the antioxidant vitamins and carotenoids in cataract prevention. Am J Clin Nutr, 53, 352S-355S.
- Rimm EB, Stampfer MJ, Ascherio A, Giovannucci E, Colditz GA & Willett WC (1993) Vitamin E consumption and the risk of coronary heart disease in men. N Engl J Med, 328, 1450-1456.
- Malafa MP, Fokum FD, Mowlavi A, Abusief M & King M (2002) Vitamin E inhibits melanoma growth in mice. Surgery, 131 (1), 85-91.
- Vega-López S, Devaraj S & Jialal I (2004) Oxidative stress and antioxidant supplementation in the management of diabetic cardiovascular disease. J Invest Med, 52 (1), 24-32.
- Gilgun-Sherki Y, Melamed E & Offen D (2004) The role of oxidative stress in the pathogenesis of multiple sclerosis: The need for effective antioxidant therapy. J Neurol, 251 (3), 261-268.
- Tidball JG & Wehling-Henricks M (2007) The role of free radicals in the pathophysiology of muscular dystrophy. J Appl Physiol, 102, 1677-1686.
- De Rijk MC, Breteler MB, den Breeijen JH, Launer LJ, Grobbee DE, van der Meché FG & Hofman A (1997) Dietary antioxidants and Parkinson’s disease: The Rotterdam study. Arch Neurol, 54 (6), 762-765.
- Yoshikawa T, Tanaka H & Kondo M (1983) Effect of vitamin E on adjuvant arthritis in rats. Biochem Med, 29 (2), 227-234.
- Watson TA, Callister R, Taylor RD, Sibbritt DW, MacDonald-Wicks LK & Garg ML (2005) Antioxidant restriction and oxidative stress in short-duration exhaustive exercise. Med Sci Sports Exerc, 37 (1), 63-71.
- Babior BM, Kipnes RS & Curnutte JT (1973) The production by leukocytes of superoxide, a potential bactericidal agent. J Clin Invest, 52, 741-744.