Antioxidants not a magic bullet for runners

November 19, 2003 in Nutrition Topics in the News, Sports Nutrition and Exercise, Vitamins, Minerals, Supplements

Antioxidants not a magic bullet for runners

Loading up on vitamins won't help athletes recover from a marathon or other endurance event, according to a North Carolina researcher. But drinking a sports drink every hour during an extreme workout may do the trick. The secret is in the carbohydrates -- mainly sugar -- found in sports drinks like Gatorade, and Powerade.

Although moderate exercise may boost the immune system, research has shown that pushing the body's limits during an endurance activity like a marathon can temporarily weaken the immune system. Because of this, endurance athletes are at increased risk of illness following an event.

When people exercise for 90 minutes or more without taking a break, carbohydrate stores in the body drop. The brain senses this decline and releases large amounts of stress hormones. The release of stress hormones leads to alterations in the immune system.

This immune effect can last as little as 3 to 6 hours or as long as 3 days. These immune system changes help explain why endurance athletes are at increased risk of getting sick after a race.

According to experts, the best way to keep the immune system strong is to maintain the body's stores of carbs during rigorous exercise. There has been hope that vitamin supplements may help endurance athletes keep their immune defenses up.

But in three studies, the researchers found that runners who took 1,000 to 1,500 milligrams of vitamin C each day for a week before a race fared no better than runners who took a dummy placebo pill. Vitamin C had no effect on the negative immune system changes or on stress. They also found that vitamin E was no help either.

The researchers recommended maintaining carbohydrate stores by drinking one liter of a sports drink for every hour of exercise. The drinks are about 6 percent to 8 percent sugar. For most people who exercise, though, sports drinks are not essential.

The immune changes that affect endurance athletes do not seem to occur in people who exercise for less than 90 minutes at a time or who take breaks during longer periods of physical activity.

All research on this web site is the property of Leslie Beck Nutrition Consulting Inc. and is protected by copyright. Keep in mind that research on these matters continues daily and is subject to change. The information presented is not intended as a substitute for medical treatment. It is intended to provide ongoing support of your healthy lifestyle practices.