Athletes should manage their hydration during prolonged exercise by monitoring their fluid intake and using electrolyte-rich beverages, especially during intense workouts. It's essential to begin hydration before exercise and continue replenishing fluid losses throughout the session. Drinking water and sports drinks can help restore lost salts and minerals. Athletes are encouraged to drink small amounts regularly rather than large quantities sporadically. Regular hydration promotes optimal physical performance and reduces the risk of dehydration and heat-related illnesses.