Thursday, January 31, 2008

Nutrition for Endurance Athletes Should Include Antioxidants

by: Dr. Keith Scott

Although adhering to a well structured training regime is the best way for athletes to achieve good results they need to look to their diets and dietary supplements to maintain good health and to improve post-event recovery. There are many different categories of supplements but perhaps the most important, and misunderstood, of these are the antioxidants. Numerous types of antioxidants occur; some are produced by our bodies while others are derived from the diet. Free radical-induced oxidative stress is an inevitable consequence of prolonged exercise and results in tissue damage, excessive fatigue, delayed recovery and overtraining. Endurance athletes need to ensure that they have an adequate intake of a wide variety of effective plant-based antioxidants.

Free radicals (including reactive oxygen species) are unstable molecules that can cause damage to DNA, cell walls and other structures. Most free radicals are by-products of the normal processes of energy production by the cell. A useful analogy is a car engine that releases exhaust gases during the process of energy production. Free radicals are the body's equivalent of a car's exhaust gases. The more work the engine does the more gases it will produce. Similarly, the harder and longer we exercise the more of these toxic free radicals we produce.

Antioxidants are substances that neutralize the harmful effects of free radicals. In order to counter the damaging effects of these unstable molecules the body has developed an elaborate antioxidant defense system. Although we produce our own (endogenous) antioxidants we also require a supply of antioxidants from our food. Some well known dietary antioxidants are vitamins A, C, E; ß-carotene, selenium and plant based antioxidants such as curcumin, quercetin, resveratrol and rutin.

One of the most important concepts we need to appreciate in this context is that we require a wide variety of antioxidants to deal with the many different types of free radicals that are released during energy production. One or two so-called "strong antioxidants" are unable to neutralize all free radical species. Furthermore not all antioxidants can reach all the parts of every cell. For instance vitamin E functions primarily in the "fatty" parts of the cell while vitamin C can only access the "watery" areas. Some antioxidants cannot cross the 'blood-brain barrier' and therefore cannot provide protection for that vital organ.

The body requires higher than normal levels of antioxidants to cope with the vastly increased quantities of free radicals produced during prolonged, strenuous exercise. One way of building up endogenous antioxidants is to exercise frequently. Athletes who train regularly have far greater quantities of endogenous antioxidants than those who exercise intermittently or not at all. As a result of exercise-induced free radical overload endurance athletes also need to boost their intake of plant-derived antioxidants. A number of clinical studies have shown that taking a wide range of plant-based antioxidants can help to counter free radical damage in endurance athletes. In addition they improve post event recovery and accelerate muscle repair – especially in older athletes.

On the other hand several clinical trials have failed to show that taking only one or two so-called "strong" antioxidants like vitamins C, E or Co-enzyme Q10 provides any benefit at all. In fact vitamin C in high doses (1000 mg per day) can be harmful as it slows post event recovery and aggravates muscle inflammation commonly associated with vigorous exercise.

Plants provide an extensive range of valuable antioxidants and natural anti-inflammatory compounds. Spices are the richest food source of these compounds followed by fruit, vegetables, nuts and beverages such as tea and coffee. Scientists have discovered that many plant-based antioxidants are vitally important in the prevention of diseases such as heart disease, cancer and Alzheimer's disease – just some of the illnesses that are associated with free radical damage. As these plant compounds are powerful, effective free radical scavengers it is not surprising that they provide benefits to athletes who are frequently exposed to free radical-induced oxidative stress.

Antioxidant variety is more important than the strength of individual antioxidants. While it is important for everyone to ensure that they have an adequate intake of antioxidants, it is unwise to take excessive amounts of only one or two antioxidants like vitamin C or E as they may do more harm than good. To ensure optimum protection against free radical damage, endurance athletes need to eat sufficient quantities of fruit, vegetables and spices and take a supplement rich in an array of different plant-based antioxidants. Spice supplements provide the most comprehensive antioxidant protection for endurance athletes.

Dr Keith Scott is a medical doctor and a a keen cyclist. He is presently researching the requirements of antioxidants in endurance athletes and has written several books including the ground breaking, "Medicinal Seasonings, The Healing Power of Spices" and "Natural Home Pharmacy". For more information and to download a free pdf copy of "Medicinal Seasonings" go to:

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