The recommended intake of water for an average adult per day is about 2.7 liters (91 ounces) for women and 3.7 liters (125 ounces) for men, including all beverages and food sources. Staying adequately hydrated is essential for maintaining optimal physiological function, including temperature regulation, joint lubrication, and nutrient transportation. Proper hydration can also enhance exercise performance and recovery, emphasizing the importance of consistent water intake for overall health.