Hydration: How I learned to love drinking 8 glasses a day

First, a confession: I've never much liked water. For as long as I can remember, whenever there's nothing else to drink, I've chosen nothing. Water is dull — it's plain, it's tasteless (except when it has a bad taste), and you can't chew it.

Even if I don't drink those sacred eight glasses a day, nothing bad seems to happen. So why, I've always thought, should I bother?

Then I tried it. Not because I was thirsty, but because I was curious. So for a month, I drank. I learned a lot about water — beginning with the fact that most of what I thought I knew was wrong.

Day 1

Operation Hydration begins with two big early-morning glasses of water. Getting eight of these babies down the hatch seems impossible, but one by one I knock them off.

My ability to glug down so much water comes as a surprise to me. "Just because you aren't thirsty doesn't mean your body doesn't need water," says E. Wayne Askew, Ph.D., director of the division of foods and nutrition at the University of Utah. "Our thirst mechanism just is not one of our better regulatory mechanisms — it tends to lag behind." He explains that by the time you're thirsty — that is, when your brain kicks in and says, "Hey, drink something" — your body fluids have already dipped.

System-wide distribution doesn't occur as soon as you drink a glass of water. In fact, water has no effect on your body until it has made its way down the esophagus, through the stomach, into the gastrointestinal tract and across the intestinal wall. That's when water begins moving, via the blood, throughout the body.

Along the way, blood fluid, or plasma (the liquid part of blood), is changing the proportion of essential salts dissolved in blood. It's the balance between your body fluids and these salt particles that tells the brain just how dry you are. In turn, the brain sends the body other signals, such as increased or decreased saliva flow, that tell us in ways we can interpret directly whether or not we're thirsty.

Day 5

I've got this down to a routine now. Two glasses in the morning, two more by noon, two before dinner, one with dinner, one before bed.

Operation Hydration wasn't such a drastic change in my water intake as I had thought. Although I flouted the eight-glasses-a-day rule, I was actually taking in lots of water from the fruits and vegetables I ate. Still, my kidneys were constantly busy with maneuvers to compensate for underhydration. For example, they put out what I now recognize as highly concentrated urine — dark yellow from the high percentage of urea or waste products. For another, they are part of a complex process that ultimately compensates for drops in blood volume and blood pressure. No wonder the kidneys are considered vital, and their development a critical event in the evolution of the species.

Day 11

Still drinking. I no longer feel bloated. For better or worse, I am eating nearly as much as I was eating two weeks ago.

As land animals, our biggest problem is not how to get rid of water but how to conserve it; we are always in a state of water loss. When we aren't sweating, we are losing water through skin evaporation. Likewise, every breath we take removes another drop or two of the moisture that coats the surface area of our lungs. More than any other element, water is what keeps us going. It is the body's transport system, the medium for the delivery of what we need — that is, oxygen and nutrients — and the elimination of what we don't need. It is one of the ways we regulate our internal temperature and avoid the meltdown that high outside temperatures, fevers or prolonged exertion might cause. And by acting as a cushion to our joints and filling both cells and intercellular space, it is what gives form to our bodies.

Continuous exposure to high concentrations of salts and minerals can contribute to urinary tract infections and the formation of kidney stones. Drinking a lot of water is one means of postponing and relieving kidney problems — a matter of growing importance, given recent increases in rates of kidney disease. "As people get older, their ability to sense low fluid balance decreases and they can become seriously dehydrated," says Dion Zappe, Ph.D., a physiologist at the drug company Astra Merck. Memory loss, dizziness, fatigue, poor cognitive function and headaches — so many of the symptoms we associate with the elderly — may stem from underhydration, not age, he says, and can often be alleviated by increased water intake.

Day 15

When I cut back my water intake for two days, I miss it. I like the spurt of energy I get from a mid-afternoon glass.

If you're losing a lot of water and are seriously dehydrated, most likely you'll be well aware of feeling thirsty. But in normal circumstances, says William Dantzler, M.D., Ph.D., head of the department of physiology at the University of Arizona, your thirst mechanism may not come into play. Often, says Todd Cameron, N.D., of the Portland Naturopathic Clinic, when people feel a little tired, on edge, slightly headachy or hungry they're actually experiencing mild dehydration. "They take a nap or maybe even snap at somebody," he says, "but what would probably make them feel a lot better is drinking a glass of water."

Even when your thirst mechanism is registering, it usually won't tell you to drink all you need. "Left to their own accord, people only replace about 50 to 75 percent of the water they've lost," says Scott Montain, Ph.D., a research physiologist at the U.S. Army Research Institute of Environmental Medicine in Natick, Massachusetts. To replace all that you've lost, he and other experts stress, it's necessary to keep drinking at least a few glasses past the feeling of thirst.

Day 22

I've been back on eight glasses a day for a week now. My urine is clear again, and I don't have that familiar uncomfortable feeling in my mouth that I've come to recognize as thirst.

Drinking lots of water can help you take better advantage of what you have in the way of health, appearance and mental functioning. The most direct impact of consuming adequate water is that it will help you feel somewhere between a little and a lot better. Chinese medicine and homeopathy place great emphasis on water's soothing effects on the body, whatever a patient's state of health.

Day 28

As Operation Hydration wears on, I notice a number of ways that my state of not-quite-enough water might have influenced how I felt. For instance, I have always found it easier to run in the winter than in summer. Of course this is partly because lower outside air temperatures keep my skin cooler, but I now wonder whether it is also because I was not exacerbating an already underhydrated state. Another example: Whenever I drank alcohol in the evening, the next morning I was likely to feel fatigued, dizzy and as if my head were exploding. These are classic symptoms of a hangover, but they are also classic symptoms of dehydration. Which is hardly surprising, considering what a powerful diuretic alcohol is. That's why many experts recommend a glass of water for every glass of wine.

I still find water on the dull side, but that doesn't really matter very much. After all, I don't take calcium for its taste; I take it for its efficacy. And when I think about water that way — drinking it not for its taste or aroma or texture but for what it does — I like it a lot.