For adequate water intake, adults need to drink 6 to 8 glasses of water a day

Fact or Opinion

It depends on gender, exercise, BMI, and sodium intake. Most clinics will give a summation averaging the above recommendation, while others will say men should have 13 cups to women's 9 cups. Most marathon training groups and modern bodybuilding groups will say it's important to stay hydrated and drink when you're simply thirsty. If you avoid sugary drinks and/or sodium drinking when your thirsty is an adequate formula.