During Exercise

Perhaps the most common error during physical activity is to delay drinking fluids until the sensation of thirst manifests itself. Besides the fact that drinking at this point is not likely to adequately hydrate working muscles during the activity , the natural response to thirst is to drink a large volume of fluid at one time. Because the thirst sensation suggests that the athlete is already dehydrated, gastric emptying will be delayed, which will make the athlete feel nauseated. In general, care should be taken to never allow thirst to occur during exercise so that consumed fluids will rapidly leave the stomach and be delivered quickly to needy muscles. Additionally, no solid foods or high-concentration carbohydrate beverages (e.g., beverages with a carbohydrate concentration that exceeds 8 percent) should be consumed during physical activity unless the athlete knows that these foods and beverages do not cause GI distress.