Sport, Antioxidants and Oxidative Damage
Exercise and oxidative damage (Full Article HERE)
Endurance exercise can increase oxygen utilization from 10 to 20 times over the resting state. This greatly increases the generation of free radicals, prompting concern about enhanced damage to muscles and other tissues. The question that arises is, how effectively can athletes defend against the increased free radicals resulting from exercise?
“Do athletes need to take extra antioxidants?”
Because it is not possible to directly measure free radicals in the body, scientists have approached this question by measuring the by-products that result from free radical reactions. If the generation of free radicals exceeds the antioxidant defenses then one would expect to see more of these by-products. These measurements have been performed in athletes under a variety of conditions.
“Several interesting concepts have emerged from these types of experimental studies. Regular physical exercise enhances the antioxidant defense system and protects against exercise induced free radical damage. This is an important finding because it shows how smart the body is about adapting to the demands of exercise. These changes occur slowly over time and appear to parallel other adaptations to exercise.”
On the other hand, intense exercise in untrained individuals overwhelms defenses resulting in increased free radical damage. Thus, the “weekend warrior” who is predominantly sedentary during the week but engages in vigorous bouts of exercise during the weekend may be doing more harm than good. To this end there are many factors which may determine whether exercise induced free radical damage occurs, including degree of conditioning of the athlete, intensity of exercise, and diet.
Results may vary
Although there is varying degrees of success in combating sport’s oxidative stress with antioxidants it seems there are some positive indicators with certain herbs & spices (like Green Tea) and Vitamin E being antioxidants that do work. The work of Obad et al suggests that antioxidants can have an effect on heart function.
“Antioxidant treatment with vitamins C and E reverses brachial endothelial dysfunction, while the reduction in the post-dive heart and pulmonary artery function is unaffected”
Other results in non-human subjects have also suggested a positive link between antioxidants and reducing oxidative stress during exercise (see Misra et al).
“Extracts of Withania somnifera, Ocimum sanctum, and Zingiber officinalis have no general toxic effect as reflected here from the study of transaminase activities in liver and kidney. Results lead to conclude that the composite extract of above three plant parts has a therapeutic protective effect on forced swimming-induced oxidative stress in vital organs.”