Electrolytes & Fluid Replacement

When we sweat, urinate, vomit and have diarrhea we lose water and electrolytes. That means following certain activities, like exercise and athletic sports, and during certain health conditions, such as heat stroke or cholera, you need to replace those lost electrolytes and fluids to maintain health. In cases of mild and moderate dehydration, drinking water or carbohydrate-electrolyte beverages may be sufficient. In cases of severe dehydration, however, immediate medical intervention, likely including emergency intravenous fluid and electrolyte replacement, might be necessary. In either case, if concerned about your electrolyte and fluid levels, seek a doctor's counsel immediately.

Electrolytes

Electrolytes are molecules that keep muscles functioning properly. They come in the form of either simple inorganic salts, like calcium or magnesium, or more complex organic compounds. In foods, electrolytes are most abundant in complex carbohydrates, though many of the inorganic mineral electrolytes are also in most fruits and vegetables.

Electrolyte & Fluid Loss

An imbalance or insufficiency in water and electrolytes can lead to conditions like hyponatremia and clinical dehydration. When dehydrated, the body lacks sufficient vital blood salts like sodium and potassium. A lack of fluids and electrolytes impairs the functioning of several organs, including the kidneys, heart and brain. Signs of mild dehydration include dry lips and thirst. Signs of moderate dehydration include sunken eyes, skin that doesn't go back into shape after being pinched and released and dry mucous membranes around and in the mouth. Signs of severe dehydration include all the preceding signs along with a weak and rapid pulse, rapid breathing, blue lips, cold extremities and lethargy or confusion.

Exercise and Other Indications

As Michael N. Sawka and colleagues at the American College of Sports Medicine point out in a Special Communication on "Exercise and Fluid Replacement," following exercise, you should always replace any loss of fluids and electrolytes. Fluid replacement might come in the form of water or from what Sawka calls "a more aggressive replacement program" consisting of carbohydrate-electrolyte loaded fluid replacement beverages, or "sports drinks." Other indications that you might need electrolyte and fluid replacement include heat stroke, diarrhea, cholera, electric shock and post-operative recovery. Factors influencing the degree and rate of fluid and electrolyte loss include genetics, body type, fitness level, environment and activity.

Water vs. Carbohydrate-Electrolyte Fluid Replacement Effectiveness

While water replenishes the body's fluid levels, it does not necessarily replenish electrolyte levels. For that, complex carbohydrates and other electrolyte-loaded foods and beverages might be necessary. A 2005 study published in "Military Medicine" comparing the effectiveness of water against that of carbohydrate-electrolyte fluid replacement, or CHO-E, on factors like hydration status and exercise performance found that CHO-E elevates blood sugar levels, thus preventing hypoglycemia. It therefore might help enhance a person's exercise endurance capacity. They also found CHO-E might help to maintain high carbohydrate oxidation rates and prevent fatigue. However, it did not help to rehydrate the body after dehydration, nor did it affect any significant physiological factors related to heavy exercise or heat stress, such as core body temperature.