I have read a statement made by the NSCA saying it is better to hydrate by gulping versus sipping. What is the physiological explanation for this?
For hydration purposes during exercise, gastric emptying rate increases with a larger amount of fluid, and since gulping provides a greater intake of fluid than sipping, gastric emptying rate increases. If an athlete sips fluid every few minutes versus gulping every 10-15 minutes, then the fluid will not empty as quickly from the stomach and will be less efficiently used.
Prior to exercise, it is recommended that athletes consume 17-20 ounces of fluid two hours before and 7-10 ounces of fluid 10-20 minutes before an event. Fluid can be in the form of water or a sports drink, but for activities lasting longer than one hour, sports drinks are preferred as they provide fluid, carbohydrates and necessary electrolytes found in sweat. Since fluid temperature influences the amount consumed, cool beverages (between 50-59 degrees F) are recommended. Gulping is still preferred in the before-exercise window, as well as during and after exercise since it influences a faster rate of gastric emptying. Sipping fluids throughout the day is preferred when exercise is not planned since gastric emptying time is not of high importance.
After exercise or an event, it is recommended to drink 20-24 ounces of fluid that contains adequate sodium and carbohydrates (1.0-1.2 grams per kilogram of body weight) for every pound lost in body weight. When rehydration is needed rapidly after exercise, the athlete should consume 25-50% more than sweat losses to compensate for obligatory urine losses within 4-6 hours after training.
- National Athletic Trainers’ Association Position Statement: Fluid Replacement for Athletes. Journal of Athletic Training, 2000, 25(2), 212-224.