 The purpose of electrolytes is to replenish the body with ions to carry throughout the body for muscle contractions and nerve impulses.Electrolytes are also a scientific term for "salts" and water is a better carrier for salts than any other liquid, so the effectiveness of what sports drinks advertise is unnecessary for normal bodily functions and may cause harm due to the high sugar content.In the 19th and early 20th centuries, athletes occasionally drank beer of low alcohol content replenishing water, minerals and energy in the body.