Do you diligently keep a water bottle handy at all times – on your desk, inside the car, beside the bed – to ensure you stay hydrated with 64 ounces of water a day? When it comes to staying hydrated, many women follow the old rule of thumb: 8 glasses of water a day. You don’t have to. It turns out the 8-cup rule may be unnecessary.
How much water is needed to stay healthy depends on you and your lifestyle, says Barbara Rolls, Ph.D., professor of Nutritional Sciences and the Helen A. Guthrie Chair in Nutrition at Pennsylvania State University. Eight glasses of water a day “are recommended to ensure that Americans consume adequate fluid each day and avoid dehydration,” says Bob Murray, Ph.D., who has done research on exercise science and sports nutrition.
Like oil lubricating a car, water improves your body’s performance. It maintains metabolic functions, including carrying nutrients to cells, eliminating wastes and regulating temperature. Your body loses water from urine – about 6.3 cups a day – sweat, bowel movements and even breathing. Fortunately, people have a warning system: If you don’t get enough water, you won’t feel well.
Common signs you’re getting dehydrated include thirst, headaches and fatigue. Urine color is another good indicator. If it’s dark yellow, you need more water. In fact, many people have darker urine in the morning, after not drinking anything for eight hours. If you aren’t thirsty and produce odor-free urine that’s slightly yellow, you’re getting enough fluids.
Darker, more concentrated urine also can lead to other health problems. That’s because it can leave bacteria behind in the urinary tract and trigger bladder irritations and urinary tract infections (UTIs).