Dehydration negatively affects physical performance by impairing endurance, strength, and overall cognitive function. Even mild dehydration can lead to decreased athletic performance, increased fatigue, and slower reaction times. It may also heighten the risk of heat-related illnesses during intense exercise or high temperatures. To optimize physical performance, it’s crucial for individuals to maintain proper hydration before, during, and after workouts, ensuring sufficient fluid intake to support bodily functions effectively.