Electrolytes are lost through sweat during intense exercise and/or high temperatures. When electrolytes are depleted from your body, you become tired, cramp easily, and are at risk for dehydration. When you become even midly dehydrated your health can suffer too. Replacing electrolytes is essential to keep your body hydrated, to enhance performance, and to help prevent muscle cramps. Electrolytes also help the brain and nervous system transmit and receive important signals and allow the muscles to contract and relax. Some studies show that electrolytes such as potassium and magnesium also support heart function.