Exercise and Oxidative Stress: Effect of Vitamin E and Aging

Previous research conducted by my colleagues and I has demonstrated that unaccustomed exercise may result in delayed onset muscle soreness resulting from microscopic tears in the muscle. We first observed this in marathon runners, who have remarkable delayed onset soreness and damage that takes up to 3 months after a marathon to fully repair. The damage results from what is called “eccentric” exercise, also known as negatives by weight lifters, and involves the muscle lengthening while it produces force. Apparently, the downhill portion of the marathon tends to cause the damage. Eccentric exercise is a natural component of all forms of exercise. Performing tasks with a high eccentric component (e.g., downhill skiing or weigh/lifting) may result in severe muscle damage and soreness the first or second time it is performed.

Because of this damage, my colleagues and I became interested in the ongoing repair process. Our experimental protocol involves having our subjects perform eccentric exercise and then examining the responses. We have seen that exercise results in muscle damage and repair and that muscle continues to show signs of damage for days after the exercise. This increasing amount of damage is likely due to an increase in the production of oxygen free radicals within the muscles.

We therefore examined the effects of vitamin E supplementation of muscle damage and repair in young and older men. Our hypothesis was that 2 months of supplementation (800 IU vitamin E/day) would make the muscle tissue less likely to exhibit damage following eccentric exercise. Although our study showed minimal effects on the responses of the young subjects, vitamin E had a substantial effect on the responses of the older men.

The adaptive response to damaging exercise involves an “acute phase response,” similar to that which people exhibit to infection. stress or trauma, and involves the immune system and its many effects. It appears that young people have a robust response to the exercise, whereas the elderly do not. Our research has demonstrated that vitamin E supplementation in the older subjects restored their response to that which was seen in the young subjects. This involved the mobilization of immune cells to invade the damaged muscle and ultimately to stimulate repair. In addition, we demonstrated that vitamin E supplementation greatly decreased the production of oxygen free radicals in both groups of subjects. Taken together, these studies reveal that vitamin E, and perhaps other antioxidant vitamins (C and beta carotene), will help to accelerate the adaptive response to exercise in the elderly and that in both young and older subjects, antioxidant supplementation may help to reduce the continued damaging effects of oxygen radicals.

Although there is compelling evidence that vitamin enhances the adaptive response to exercise, there is little evidence that vitamin E serves as an ergogenic aid during exercise. Vitamin E supplementation has not been demonstrated to enhance endurance, anaerobic, or strength exercise performance, nor is there any scientific rationale to believe that it has any ergogenic effects.

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Written by William J. Evans PhD

Explore Wellness in 2021