Water is often seen as the key to optimal hydration. While water is important, electrolytes are critical when it comes to properly hydrating. Electrolytes help to replace sodium, potassium, calcium, magnesium and chloride that are lost through sweat. Without adequate electrolytes, dehydration can be a concern. Dehydration can cause serious health issues such as heat exhaustion, heat stroke, reduced autonomic cardiac stability, reduced cerebral blood flow and rhabdomyolysis. Athletes who don’t replace sodium lost in sweat can suffer from hyponatremia. This is a concern in athletes involved in high intensity, ultra-endurance events that only consume water. Hyponatremia is occasionally seen in football and tennis players who overdrink water to prevent heat cramps (1).

Alcohol consumption increases the body’s urine output by inhibiting the release of antidiuretic hormone (ADH), known as vasopressin. The reduced vasopressin levels then prevent the kidneys from conserving water. The regulation of the volume and composition of body fluid is one of the key functions of the kidneys. This increased urine output can alter the body’s hydration state and produces disturbances in electrolyte concentrations (1, 2).

Consuming excessive amounts of alcohol can also result in sweating, vomiting and diarrhea. These conditions can result in additional fluid loss and electrolyte imbalances as well (1,2).

Cramping can be an uncomfortable side effect of exercise. High intensity exercise often leads to the loss of fluid through sweating and can lead to electrolyte imbalance caused by severe dehydration. Cramping is more likely to occur in individuals who sweat heavily and lose a higher than normal amount of sodium and other electrolytes such as potassium, calcium and magnesium in sweat (1). Supplementing with electrolytes can help to correct the imbalance and alleviate cramping.

Sweat is the mechanism the body uses to cool itself during bouts of physical activity. This is why high intensity physical activity and warmer temperatures lead to sweating. In addition to losing fluid when we sweat, we also lose electrolytes like sodium, potassium, calcium, magnesium and chloride.

Sodium is the most widely lost electrolyte in sweat, and for that reason, it’s typically included in sports drinks formulations. In addition to replenishing lost sodium levels, the intake of sodium stimulates thirst and helps the body retain water (1).