Besides helping your body run smoothly, there's some evidence that water helps prevent certain diseases. People who have had kidney stones can prevent further stones from forming by drinking lots of fluid. And in one study, women who drank more than five glasses of water a day had a risk of colon cancer that was 45 percent less than others in the study who drank two or fewer glasses a day. In another study published in the New England Journal of Medicine , men who drank at least six glasses of water per day cut their risk of bladder cancer in half compared with men who drank less than one glass, regardless of how much of other liquids they consumed. Concentration and endurance begin to waver, muscle cramps set in prematurely and other dehydration-induced injuries may follow.
Sports drinks are useful when consumed after or during vigorous and prolonged exercise in high heat.
But most experts agree that water works better than carbohydrates or sugared beverages for moderate exercise. For instance, if you drink 12 ounces of plain water, your body will absorb 8 ounces of it within 15 minutes. Water suppresses the appetite naturally and helps the body metabolize stored fat. Studies have shown that a decrease in water intake will cause fat deposits to increase, while an increase in water intake can actually reduce fat deposits. Most drinking water in the United States is safe to drink, but it's always a good idea to check with your local water authorities and with the U.S. Geologic Survey.