Originally Posted by Wikipedia
Electrolytes are commonly found in sports drinks. In oral rehydration therapy, electrolyte drinks containing sodium and potassium salts are used to replenish the body's water and electrolyte levels after dehydration caused by exercise, diaphoresis, diarrhea, vomiting or starvation. Giving pure water to such a person is not the best way to restore fluid levels because it dilutes the salts inside the body's cells and interferes with their chemical functions. This can lead to water intoxication.
Sports drinks such as Gatorade, Powerade, or Lucozade are electrolyte drinks with large amounts of added carbohydrates, such as glucose, to provide energy. The drinks commonly sold to the public are isotonic (with osmolality close to that of blood), with hypotonic (with a lower osmolality) and hypertonic (with a higher osmolality) varieties available to athletes, depending on their nutritional needs.
It is really not necessary to replace losses of sodium, potassium and other electrolytes during exercise since it is unlikely that a significant depletion the body's stores of these minerals will occur during normal training. However, in extreme exercising conditions over 5 or 6 hours (an Ironman or ultramarathon, for example) the consumption of a complex sports drink with electrolytes is recommended. Athletes who do not consume electrolytes under these conditions risk overhydration (or hyponatremia).
Because sports drinks typically contain very high levels of sugar, they are not recommended for regular use by children. Rather, specially-formulated pediatric electrolyte solutions are recommended. Sports drinks are also not appropriate for replacing the fluid lost during diarrhea. The role of sports drinks is to inhibit electrolyte loss but are insufficient to restore imbalance once it occurs.[citation needed] Medicinal rehydration sachets and drinks are available to replace the key electrolyte ions lost. Dentists recommend that regular consumers of sports drinks observe precautions against tooth decay.
Electrolyte and sports drinks can be home-made by using the correct proportions of sugar, salt and water.