Thirst Quenchers
Good health depends on getting enough water every day

By Claire Walter

You drink a big glass of juice for breakfast, sparkling water for lunch, a sport drink during your afternoon workout, and milk or water with dinner. That should be enough liquid for one day—or is it? Consider this: Roughly two-thirds of the average adult's body weight is water; every day, up to two-and-a-half quarts are spent through perspiration, urination and exhalation.

Because the body has no reservoir, water must be steadily replaced. But while most people know they should be downing eight to ten glasses of water every day, the average American drinks only 4.6 glasses daily—not nearly enough. (A "glass" is equivalent to eight fluid ounces, as is a cup.)

Water is critical to health—and is chronically overlooked. Second only to air in its steady and relentless necessity, H2O carries nutrients to cells; aids digestion by contributing to stomach secretions; flushes bodily wastes and reduces risk of kidney stones by diluting salts in the urine; ensures healthy function of moisture-rich organs (skin, eyes, mouth, nose); lubricates and cushions joints; regulates body temperature; and protects against heat exhaustion through perspiration. And the list goes on and on.

Fountain of health Water does more than wet your whistle. When your body's water need becomes pronounced, symptoms can include low blood pressure and fainting; chronic dehydration can cause hypertension, asthma, allergies and migraines. Make sure you meet your body's water needs. Lisa O'Donnell, RD, of Arizona's Miraval Life in Balance Spa, calls water "the forgotten nutrient." It could also be called "the forgotten preventive," neglected despite its well-documented role in warding off a host of ailments, including allergies, constipation and possibly even certain cancers. In one study, women who drank more than five glasses of water daily reduced by half their risk of colon cancer compared with women who drank two glasses daily (Cancer Epidemiology, Biomarkers & Prevention, 1996, vol. 5, no. 7).

High And Dry
Despite its importance and availability, "people are walking around drinking no water at all," says Christine Palumbo, RD, who runs a nutrition practice in Naperville, Illinois. Part of the problem is timing. If you wait until your mouth feels dry before reaching for the water bottle, "you're already slightly dehydrated because the sense of thirst lags behind your body's need," says Palumbo. Other signs of mild dehydration include a flushed face, restlessness or irritability, dry or warm skin, strong-smelling and dark colored urine, dizziness, weakness and headache.

When Eight Isn't Enough
Under regular conditions, the typical person needs a minimum of 1/2 ounce of water per pound of body weight daily, roughly eight to ten cups, "at least half of which should be plain water," says Palumbo. But pay attention to these additional factors, which can increase that requirement:

Exercise. Because working out burns water quickly, you should drink eight ounces of water before you start, plus 1/2 cup every 20 minutes during exercise. Drink another eight ounces within 30 minutes of finishing. Also be aware that you might need to replace electrolytes (salts) lost through extended strenuous activity (see "Long May You Run").

High elevation, heat and humidity. Environmental conditions greatly affect your body's water usage, so drink one to two cups more daily if you're at an elevation above 5,000 feet, if the temperature exceeds 80 degrees or when humidity is low.

Pregnancy or lactation. If you're expecting a baby, your body needs an extra cup of water daily; increase by three to four cups if nursing

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Caffeine or alcohol. Because these act as diuretics, drink 1/2 cup water for every cup of these beverages to compensate.

Illness. Drink twice your recommended amount if you have diarrhea and an extra cup for every degree of fever over 100 to guard against dehydration and help flush out impurities.

Plain Or Pumped?
All experts agree that drinking enough water is crucial to health, but the debate continues as to whether plain water is the only way to gulp. "I like water because it's pure—no calories, no caffeine, little or no sodium," says Palumbo, "but other beverages do help as well," including juices, broth-based soups, even water-rich foods like lettuce and melons.

The newest bubbles in the water business are so-called "fitness waters." For example, "oxygenated" waters claim to energize and refresh by increasing the amount of oxygen in the blood.

Fruit-flavored waters promote taste appeal, thereby encouraging consumers to drink more. Other specialty waters are ratcheted up with caffeine to provide a coffee kick in a glass of water. And boutique waters are laced with combinations of herbs, minerals and vitamins and are formulated to increase strength or stamina, reduce stress or fatigue, enhance brain focus and the like. Whatever your choice, it's getting it down that counts, so drink to your health.

Claire Walter is an award-winning writer specializing in sports, food, and fitness. Her books includeThe Complete Idiot's Guide to Fitness (Alpha Books, 2000).