Drinking Water: Are You Doing it Right?

Is it true that I'm supposed to drink 8 glasses of water a day?

No. "Eight a day" is a myth. What you really need is enough fluid to replace what you lose each day in your sweat, urine, breath, and other bodily excretions. That's about 8 to 10 cups of water. Since we get about 4 cups' worth from fruits, vegetables, and other foods, that leaves 4 to 6 cups for you to make up with beverages. Tea, coffee, juice, even soda count (though it's also smart to avoid empty calories) toward your total. Of course, you may need more in hot weather or if you're exercising or being more physically active than usual. So if you're still thirsty, sip more.

Is it true that drinking too much water is dangerous?

Fact. "Water intoxication" is common among marathon runners, but it can also happen to anyone who's exerting themselves for an extended period and guzzling lots of H2O. Physical stress like exercise reduces the kidneys' ability to send urine to the bladder for excretion. Drink too much, and fluid levels could build in your body and brain, making brain cells swell and leading to headaches, nausea, vomiting, disorientation, and in some cases, death. To avoid it, drink enough to quench your thirst, not gallons. And if you need to drink large amounts of fluid, use Gatorade, Propel, Powerade, or other similar drinks that have vitamins and electrolytes besides just water.

PLUS: Cold Water Remedies

Should I use a water filter at home?

Yes, if water tests show that your drinking water contains pollutants or if it has an unpleasant taste or color. The right filter can remove impurities and toxins, including bacteria, copper, lead, mercury, parasites such as Giardia and Cryptosporidium, pesticides, radon, and volatile organic chemicals such as methyl-tert-butyl ether (MTBE) and dichlorobenzene and trichloroethylene (TCE).

There are many types of filters on the market, from activated carbon filters that fit on your faucet to whole-house "anion exchange" systems, so your first step is to learn what you need to filter out of your water. Ask your local water-treatment authority for a report on your water quality. If you're on a private well or want more in-depth information, consider hiring a private water-testing company.

If you simply don't like the way your water smells or tastes, an activated carbon filter may be all you need in order to enjoy your drinking water again.

Why can't I cook with hot tap water? Why must it be cold, even if I'm going to heat it anyway?

Hot water can dissolve tiny amounts of lead from your plumbing system. Older homes may have lead pipes, but even new plumbing that's lead free can still contain lead in brass fitting or faucets or in copper pipes with soldered joints. In one study, tap water accounted for up to 20 percent of human exposure to lead. Boiling doesn't help in faceit can further concentrate lead, which can damage your brain and nervous system. If you're using a faucet that hasn't been in use for the past 6 hour or some, first flush the piped by letting the cold water run until it's as cold as it will get.