Hydration plays a critical role in physical performance during exercise by regulating body temperature, supporting muscle function, and maintaining energy levels. Dehydration can lead to decreased endurance, increased fatigue, and impaired coordination. Water helps transport nutrients, flush out waste, and lubricate joints, which is essential for optimal physical function. Athletes and active individuals should aim to stay well-hydrated before, during, and after exercise to enhance performance, optimize recovery, and reduce the risk of heat-related illnesses.