When a person walks into a supermarket, they can be faced with entire walls of different types of water. Two main types of water--electrolyte and purified--are quite different in what they contain and when they should be used.
Electrolyte water is water that has had key electrolytes added to it. Electrolytes are needed by the body to complete physical processes, and they play a role in how water is absorbed into the body. Electrolytes that often are added to electrolyte water include sodium and potassium.
Purified water is water that has had chemicals removed. The chemicals removed include substances such as fluoride that, in large amounts, can be harmful. Water is purified in a variety of techniques such as deionization and distillation.
The main difference between electrolyte water and purified water is that the process of purification leaves purified water with fewer electrolytes than electrolyte water. If a person wants to absorb water most efficiently in a short time period, drinking purified water thus can be problematic, since it does not contain the substances that help water absorption (e.g., sodium). However, electrolyte water may not be as free from the harmful chemicals that are filtered out of purified water.
When They're Needed
Most people get enough electrolytes without drinking electrolyte water, so drinking purified water usually is sufficient for plain, everyday hydration. The exception is if an individual is exercising under extreme conditions, such as a marathon runner who is engaging in physical activity for more than 60 minutes. Even then, regular purified water still is necessary before, during and after exercise. Thus, if a physical trainer insists that all you drink is electrolyte water, then they probably are not sufficiently educated about how electrolyte water works or when it is needed.
When to Use Each
Electrolyte water and similar liquids (e.g., sports drinks such as Gatorade), if consumed, should be taken during exercise rather than before or after. Water, in comparison, should be taken before, during and after exercise, regardless of how intense or long the exercise regimen may be. This means that the majority of liquids ingested for hydration related to exercise should be purified water, not electrolyte water. Both electrolyte water and purified water should be taken every 10 to 15 minutes when used.
Availability and Cost
Electrolyte water and purified water are available at most supermarkets and grocery stores. On average, electrolyte water tends to be more expensive, but if a purified water has additives such as carbonation or flavoring, then the cost of purified water can equal that of electrolyte water.