2Signs of dehydration include mental and physical fatigue, lack of coordination, and sports performance decreases when a minimum of 2 percent body weight is lost from dehydration.
As a person perspires, he or she is not only sweating out water but important minerals such as sodium, potassium, magnesium and calcium. Preventing dehydration requires consumption of fluids before, during and after exercise.
Recommended guidelines from ACE Fitness include drinking 17-20 ounces two hours before exercise, 7-10 ounces every 10 to 20 minutes during exercise and 16-24 ounces for every pound of body weight lost. The best fluid to drink is water due to the skeletal muscles consisting of 75 percent water. Water not only aids in eliminating waste from the intestines, but it also transfers nutrients to cells.
According to the Food and Nutrition Board, women should consume 2.7 liters (91 ounces) and men 3.7 liters (125 ounces) of water daily. Approximately 80 percent of water should be from liquids and only 20 percent should derive from food. Important high moisture foods to get water from are melons, oranges, apples, pears, cucumbers, cabbage, soups and moist meats.
Individuals or families exercising in extreme heat should not only drink water, but should recognize their mental and physical state.
If a person profusely sweats, it is noticeable that there are salty sweat rings on the T-shirt or notice salt buildup on the skin. This might be an indicator for the need of a sports drink to recharge electrolytes and sodium.
Families that leisurely walk the park may only need to consume water.
Families should designate one sport drink per game or practice for a child who is exercising outdoors with football, tennis, soccer or cross country. Overloading on sports drinks is unhealthy, plus it adds excessive calories or sugar to the diet.
From a trainer's perspective, adolescents should drink water during a game or match and drink one uncaffeinated sport drink after the game -- only if needed.
One study conducted in the Netherlands tested male cross country runners with three separate groups drinking water, sports drinks and caffeinated sports drinks. Results showed high complaints of gastrointestinal problems and cramps with the group that drank sports drinks.
There has been minimal scientific research proving if sports drinks are the "best." Families should read the food label and pay attention to the carbohydrate percentage. Performance drinks containing less than 5 percent carbohydrates will not sustain enough energy to enhance performance. Drinks that contain more than 10 percent carbohydrates are associated with nausea or cramping during exercise. This includes Red Bull, acidic juices and soda beverages.
Caffeinated beverages such as coffee, teas, soda and caffeine drinks act as a diuretic. An effective way to check hydration is through the color of urine. Dark, gold color urine means a person is dehydrated. Light to clear color urine acts as a sign of hydration. Caffeine drinks and alcohol will create light-colored urine although a person is on the path to further dehydration. A general rule of thumb is that it takes two 8-ounce glasses of water to rehydrate the body after one 8-ounce glass of a diuretic.
Marathon runners, triathletes and cyclists not only have to pay attention to dehydration, but also to hyponatremia or water intoxication. In 2005, the New England Journal of Medicine found that 13 percent of runners in the Boston Marathon developed hyponatremia -- too little sodium in the body -- from high water consumption. These athletes can lose up to two grams of sodium per liter of sweat. In this instance, a sport drink is needed to replenish the lost nutrients.
Signs of hyponatremia are similar to dehydration with disorientation, slurred speech and cramps. Extreme circumstances of this ailment result in comas, seizures or death. Consuming sodium and sport drinks after intense training is recommended.
Overall, hydration is a tricky issue, but following recommended guidelines is safe and proven to aid in optimal performance.
Elizabeth Kovar has been working in the fitness industry since 2006 with international experience in India and Australia. She has a master's degree in recreation and tourism and is a programs coordinator at the YMCA where she trains, instructs fitness classes and assists in marketing projects. She welcomes questions and comments and can be reached at firstname.lastname@example.org.