Hydration needs vary by individual and activity level, influenced by factors such as age, gender, climate, and exercise intensity. Generally, adults should aim for a daily intake of 2-3 liters, but athletes and those engaged in intense workouts may require more. Recognizing signs of dehydration like fatigue, dizziness, or headache is essential, as these can affect performance. It’s crucial to replace fluids lost during exercise and maintain hydration throughout the day. Individual needs can also be assessed based on sweat rate and environmental conditions, ensuring optimal hydration levels.