Electrolyte Drinks Vs. Pure Water

Many people continue to believe that heat stress and dehydration can be prevented by drinking pure water. Pure water is absorbed from the stomach slowly and cannot be retained in the extracellular cavity. The water is absorbed into the intracellular cavity to preserve the proper concentration of electrolytes.

To substantiate this is the following statement from the medical text book "Medical Physiology, 20th Edition" written by Vernon B. Mountcastle:

"It is obvious that replacement of body fluids by water alone is totally inadequate. Water alone cannot be retained in the extracellular compartment and so it diffuses into the cells. For instance, the patient with diarrhea who satisfies his thirst by ingesting large volumes of water develops hypolarity of the body fluids which may lead to a state of water intoxication.

Thus, the subject, though water-logged, is still in a state of dehydration because of the shrunken condition of the extracellular fluid level. To restore the body fluids, the water must be accompanied by electrolytes. This supplies not only the lost extracellular sodium chloride, but also the intracellular potassium."

Electrolyte Drinks VS. Soft Drinks

Although soft drinks are capable of providing one with carbohydrate food energy, they are largely empty calories. On the other hand, electrolyte drinks are conservative in their caloric content, ranging from 50-70 calories per serving versus soft drinks which can have up to 120 calories per serving.

Futhermore, soft drinks may even make a person more thirsty because of the extra solute entering the fluid environment surrounding the body cells. Too high a concentration of solute in the extracellular fluid to leave the cells, thus dehydrating them even more resulting in a heightened thirst response in the individual. Additionally, soft drinks are usually very costly and rarely contribute any of the mineral salts (electrolytes) badly needed by a victim of heat stress.

About Dehydration