The human body is more than 50% water. As we age, the percentage of water slowly decreases, with babies having about 75% water and adults about 55-60%. Normal body function depends on adequate fluid balance. How can we maintain a healthy fluid balance?
In general, it is advised that adults consume about 64 ounces of water daily or 8 eight ounce glasses daily. Adequate fluid intake will help flush toxins from the body, maintain healthy organ function and replace fluid lost through breathing, sweating, urination and bowel movements.
The amount of fluid required depends on a number of factors including activity. Athletes and those of us who try to exercise can lose large amounts of fluid through sweat. Subsequently, larger amounts of fluid need to be consumed. As we work our muscles, heat is produced. The body naturally tries to cool itself through the evaporation of sweat on the skin. Also, exercise can increase the byproducts of metabolism specifically lactic acid. Lactic acid makes the muscle fatigue and can lead to muscle cramping. Providing supplemental sugar helps to replace the stored sugar in the muscles and the fluids help flush out the lactic acid. Athletes realize that their performance declines as their hydration status declines. Therefore fluid replacement has become a major priority for sports enthusiasts and competitive athletes.
Water is still an excellent source of fluid for rehydration. However water does not replace the salt and electrolytes that are lost in sweat. This was recognized and sports drinks, like Gatorade, that contain electrolytes and sugar were developed. These have been shown to provide more rapid rehydration than water alone. These are effective for oral rehydration even when people are dehydrated from illness.
Gatorade is the original sport drink. Gatorade now promotes a series of supplements for athletes. The “primer” is promoted to be used before an activity and has some sugar, electrolytes, and B vitamins. Then original Gatorade is used during the activity to provide fluid, sugar, and electrolytes. Then a “recovery” drink that contains sugar, electrolytes, and also protein for muscle repair and building is used after the activity. These supplements can be expensive and have limited evidence of their effectiveness for the average sports enthusiast. Interestingly, milk has sugar, electrolytes, and proteins making it an excellent post workout drink.
What about energy drinks? These are mostly combinations of caffeine, herbs, vitamins and sugar. Caffeine is a stimulant that has been shown to increase alertness and is the element that provides the feeling of increased energy. However, caffeine is a diuretic that can promote dehydration. Mood changes, arrhythmias, insomnia, addiction, and stomach upset have all been reported as side effects from the caffeine in energy drinks. Children are especially prone to the side effects. Even though caffeine has been shown to possibly have some beneficial effects in adults, when used in moderation, energy drinks are not recommended as part of a healthy lifestyle. Also, energy drinks used prior to physical activity will promote dehydration. Likewise, alcohol promotes dieresis and is a poor fluid for hydration purposes.
Adequate hydration is an important part of healthy living. Drink fluids before, during and after vigorous exercise. Energy drinks do not provide hydration and can worsen fluid balance because of the diuretic effects of caffeine.