Overview of Hydration
Staying hydrated is critical to maintaining optimal health. Sixty percent of the body and seventy percent of the brain is composed of water. Water is an essential nutrient that mediates a number of important physiological processes such as regulating temperature, digestion, removing waste and lubricating joints. Throughout the day you may lose up to 2.4 liters of water, as a result of sweating, urinating, and even breathing, according to MayoClinic. Exercise, especially in warm temperatures can accelerate this daily fluid loss. The failure to replenish these lost fluids can result in dehydration, which can lead to dizziness, fatigue, or in extreme cases, loss of consciousness. As such, drinking water and in some cases sports drinks, is critical for rehydrating the body and staying healthy.
Besides oxygen, water is the most important nutrient for attaining optimum health. The Institute of Medicine recommends that women consume approximately 2.7 liters (91 ounces) of fluids a day and men consume approximately 3.7 liters (125 ounces), which includes water from other beverages and water-containing foods. An easy to remember guideline for water intake is the "8 x 8 rule," which means you should drink an average of eight, 8-ounce glasses of water a day, and is equivalent to about 1.9 liters. It is especially important to remain hydrated while exercising as the body loses fluid through sweat. The American College of Sports Medicine recommends drinking about 17 ounces of fluid two hours beforeexercise, and 16-to-32 ounces of water per hour during exercise. For one hour of moderate exercise, water alone should provide sufficient hydration. In general, the absence of thirst and the production of regular light-colored urine is a good gauge of adequate hydration
Sports drinks are beverages that are designed to help replenish fluids and nutrients that are lost from the body through sweat as a result of vigorous exercise. Sports drinks contain three main components: water, sodium, and carbohydrates (your body's energy store). The National Athletic Training Association recommends that the carbohydrate content of a sports drink should be between 5-to-8 percent. A carbohydrate content that is lower will not have an effect on the body and a higher carbohydrate content will impede the absorption of fluids. The sodium in sports drinks enhances the body's ability to retain water. There are three major types of sports drinks:
- Isotonic sports drinks contain the same amount of sugar and sodium that is normally found in the body. This type of sports drink is absorbed at a slow pace, providing longer-lasting energy
- Hypertonic sports drinks contain a higher amount of salt and sugar than normally found in the body. This type of sports drink is absorbed the slowest and will provide a long-term boost energy boost.
- Hypotonic sports drinks contain a lower amount of salt and sugar than normally found in the body. This type of sports drink is absorbed quickly and will provide a short boost of energy.
Most sports drinks are moderately isotonic, containing approximately four to five teaspoons of sugar per 250 milliliter serving. Sports drinks are recommended for those who participate in intense physical activity for more than an hour. They not only replenish the fluids lost through sweat, but also many electrolytes and carbohydrates. The loss of electrolytes and carbohydrates may contribute to fatigue, confusion and cramping.
Water versus Sports Drinks
Drinking water is recommended to help maintain hydration on a daily basis and during low intensity exercise for a short period of time. Sports drinks should only be consumed by those participating in vigorous exercise for an extended period of time and/or in high temperatures. Sports drinks can actually be detrimental to your health if consumed everyday due to their high sugar and caloric content. Consuming one bottle of a sports drink may replace all the calories burned in an average workout. To offset a 60-to-120 calorie beverage, a person weighing 165 pounds would have to swim for fifteen minutes, run for ten minutes and walk for thirty minutes, according to a report in USA Today.
Drinking plenty of fluids and staying hydrated is an integral part of a healthy diet. The amount and type of fluids necessary to stay adequately hydrated varies from individual to individual. In general, men and women should try to drink approximately 125 ounces and 91 ounces of fluids per day, respectively. As your activity level and perspiration increases, your daily fluid intake should also increase by 12 to 20 ounces. When exercising, it is suggested to drink plenty of fluids, before, during, and after your workout to prevent dehydration. In general, water is recommended for daily consumption and for those who exercise moderately for a short period of time. For intense workouts that last longer than an hour, sports drinks are often preferred. These drinks help replace the fluids, carbohydrates and electrolytes lost as a result of vigorous activity.