Nutrition For Endurance Athletes Should Include Antioxidants
Sunday, 07.01.2007, 11:43am (GMT)
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.
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