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.
In general it is advised that adults consume at least 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. A good sign of adequate hydration is having relatively clear urine.
The amount of fluid required depends on a number of factors including activity. Athletes and those who are physically active in the heat can lose large amounts of fluid through sweat. Subsequently, larger amounts of fluid need to be consumed. As we work out, our muscles produce heat. 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 muscles fatigue and can lead to muscle cramping. 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. It is best to drink fluid before, during, and after a vigorous event.
Water is still an excellent source of fluid for hydration. However water does not replace the salt and electrolytes that are lost in sweat. This was recognized and sport drinks, like Gatorade, that contain electrolytes and sugar were developed. These have been shown to provide more rapid rehydration than water alone. These are even effective for oral rehydration when individuals are dehydrated from illness.
Gatorade is the original sport drink. It was developed for the University of Florida Gators’ athletes and that is how it got its name. Gatorade now promotes a series of supplements for athletes. The “primer” is promoted to be used before an activity and has some carbohydrate, electrolytes, and B vitamins. Original Gatorade is promoted to be used during vigorous activity to provide fluid, sugar, and electrolytes. Now there is a product known as G2 that has less sugar but still has the fluid and electrolytes. The last of the Gatorade series is meant for recovery after an event. This provides fluid, carbohydrates, and protein for muscle recovery and repair. The 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.
For the average weekend warrior, water is still an excellent source of hydration. Remember that the sugar in sports drinks can inhibit efforts to lose weight since sugar is a carbohydrate providing calories.
Energy drinks and drinks with caffeine are not good for hydration since caffeine acts as a diuretic. Additional water should be consumed if caffeine is taken. Likewise alcohol acts a diuretic and is not good for hydration. Adequate hydration is an important part of healthy living. To stay hydrated, strive to get at least 8 glasses of water daily. Stay healthy my friends.
By: P. Michael Shattuck, M.D. – Community Health Network Family Physician
