How much water should I drink?

Water is great medicine, needed to maintain a healthy body, a clear mind, and a good balance within your tissues. There's more water in your body than anything else, with every cell containing mostly water. About 60 percent of your body is water, and you must constantly replenish the supply, as it's used up in the processes of life. Many people fail to drink enough of it.

When you don't have enough water in your body, your cells start to draw water from the bloodstream. The blood gets sludgy, your heart has to work harder, and your body starts to redirect blood away from less vital areas. Dehydration can set in even before you start to feel thirsty. This is a great strain on the body because it impairs the kidneys in their vital function of purifying the blood and helping the body get rid of toxins.

If you've lost just 2 percent of your body weight in water, your brain power and performance level may start to weaken. Another 4 to 7 percent may leave you feeling dizzy.

The standard recommendation is to drink at least eight, 8-ounce glasses a day. I'm not sure you need to force that much down, but do try to drink as much as you can, and more than you think you need. When you're exercising, you need even more water because you're sweating and losing water through deep breathing. Of course, warm temperatures also increase water loss. Just walking for an hour on a warm day may increase your requirement by two glasses or more. An hour of tennis could require anywhere from two to ten extra glasses.

Drink extra water whenever you think of it. When you start to notice an increase in urination, you're doing a good job. Even better, you'll notice your urine lightening up, looking less concentrated. Some people keep two quarts of water in the refrigerator and make sure they empty them every day.

Also, keep in mind you don't have to limit yourself to water. You can drink highly diluted fruit juice, herbal tea, or a well-watered-down sports drink. Sparkling water with a little fruit juice or lemon is also nice. All of these count toward your 64 ounces a day. Drinks like cola, though, work against the count, because caffeine is a diuretic and removes fluid from the body. Three cups of coffee or tea are comparable to just two cups of water.

While you're doing all this drinking, make sure you're not adding new toxins to your body. Drink high-quality bottled water or, better, get a water-purification system for your home.