Electrolytes are minerals like sodium, potassium, and magnesium that play a key role in hydration and fluid balance in the body. During physical activity, electrolytes help maintain osmotic pressure, aiding in the transmission of nerve impulses and muscle contractions. They also assist in regulating blood volume and preventing dehydration. An imbalance in electrolytes can lead to complications such as cramps, fatigue, or in severe cases, heat-related illnesses. Thus, proper hydration often involves replenishing these essential minerals, especially during intense exercise.