Water Wisdom

How well do you know your H20? Our expert Q & A reveals the path to hydration salvation.

There’s bottled, tap and filtered. Flat, mineral, flavored and vitamin-infused. No doubt about it—the world’s oldest beverage ain’t as simple as it used to be. Of course, with so many options out there,we have little excuse for not meeting our aqua allowance.

As 65 percent of the human body, water is vital to our well-being—it circulates through the blood to transport nutrients and remove waste. But while water itself may be crystal clear, the facts on just how much we need often are not. To get the truth, we turned to a number of experts. Read on for their water wisdom.

Q: How much do I need to drink each day?

A: There isn’t a one-size-fits-all answer—age, gender, activity and environment are all factors—but there are a few rules to offer guidance. “The old teaching used to be eight 8-ounce glasses, but that had little science behind it,” explains Richard Scott, M.D., president of the Medical Society of New Jersey. “The Institute of Medicine suggests 3 liters [about 100 ounces, or 12 glasses] for men and 2.2 liters [about 75 ounces, or nine glasses] for women to replace the water lost each day. But remember that we also get about 15 to 20 percent of water from the foods we eat.”

For a simple solution, Julie Burns—a registered dietitian and president of SportFuel, an Illinois-based sports nutrition firm that’s worked with Chicago’s Bulls, Bears, White Sox and other organizations— recommends this formula: “Take your body weight and divide it by two to get the number of ounces you need per day,” she says. “So a 150-pound person would need 75 ounces (about nine 8-ounce cups) of water.”

Q: How much should I drink during exercise?

A:  A good rule of thumb is to consume between 4 and 10 ounces of water for every 15 minutes of exercise says Kristen E. D’Anci, Ph.D., research associate in the nutrition and neurocognition laboratory at Tufts University. When it comes to sports drinks, sip sparingly. “Gatorade and PowerAde contain fructose and sucrose,” explains Dr. Scott. “They do effectively rehydrate, but they also contain calories. For a brisk 30-minute walk, you’d ingest as many calories as you just burned!”

Q: Does it matter when I drink my water?

A: “The best way to stay hydrated is to never get behind,” says Dr. Scott. “Frequent small drinks of water throughout the day are a better way to go than one or two large portions.” That’s because consuming water too quickly can disrupt electrolyte balance. As Dr. Scott says, “You don’t sweat by the gallon, so drinking by the gallon does not make physiological sense.”

Q: Does water alone count toward my daily fluid requirements?

A: Not a huge fan of flavor-free sipping? Fear not. In 8 foods that help you stay hydrated 2004, the Institute of Medicine decreed, “The fluids consumed do not have to be only water; individuals can obtain their fluids from a variety of beverages and foods.” D’Anci recommends adding lemon or lime slices to your glass for added taste but no caloric increase. Also try different types of water—flavored, mineral and carbonated— for variety. Herbal tea and juice can maintain the body’s hydration, as can water-rich fruits, vegetables and soups.

Q: How do I know if I’m becoming dehydrated?

A: Signs can range from the obvious—dry mouth, irritability, dark urine color—to the obscure, like hunger pains experienced shortly after eating. Says Dr. Scott, “Mild dehydration (a water loss equal to 3 to 5 percent of your total body weight) may cause thirst, decreased urination and dry skin. If someone feels cool and clammy when they should be sweating, watch out! “Moderate to severe dehydration, an 8 to 10 percent loss of body weight, may lead to lethargy, rapid pulse and increased breathing,” he adds. “Losses of 12 to 15 percent are associated with hemodynamic collapse [a condition in which a decreased amount of blood circulates to the heart, leading to reduced cardiac output] and possible death if not treated emergently.”

Q: Is it possible to drink too much water?

A: Yes, but it’s uncommon. You may recall the news story last year of a 28-year-old California woman who died after participating in a water-drinking contest held by a local radio station. “Water intoxication occurs when you’ve had enough water and/or lost sufficient electrolytes to dilute the sodium levels in the blood,” says D’Anci. The condition most commonly affects infants under 6 months of age and athletes who sweat profusely during arduous activity. “But it virtually never occurs in a recreational athlete who works out 45 to 90 minutes a day,” notes Dr. Scott.

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