Tuesday, July 13, 2010

Can You Drink Too Much Water?

It’s hot. You need to drink more water, right? Most of us do need more water at this time of the year but surprisingly you can drink too much. What happens when people drink too much water is that it dilutes out the sodium in the blood to a level that is too low. This very low level of blood sodium can cause nausea, vomiting, headaches, convulsions, and even the brain to swell. Some of these symptoms are the same as dehydration, which is also dangerous. So how do you know if you’re drinking enough, but not too much, water?

Water & fluid guidelines:

 Follow your thirst. Thirst is actually a pretty good indicator of whether or not you need fluids. An exception to this is older people who may not know their bodies need fluids & can become fluid deficient pretty quickly, particularly in hot weather.

 Drink fluids during activity. Whether you’re out walking, gardening, or running a marathon, you should drink fluids before & during activity – roughly 4 to 6 ounces every 20 minutes. You don’t need gallons of water during activity – which is where some people have gotten into trouble with over hydration.

 Weigh yourself after activity. If you sweat a lot during physical activity, you can lose a lot of water weight. Drink 16 ounces of water for every pound lost during exercise.

 Check your urine. When you are well hydrated, your urine should be pale to clear. This is the best way to tell if you have had enough water. Don’t drink excessive fluids beyond this. If your urine is dark or very small in volume, then you need more fluids!

 The 8-cups of water myth. While the average fluid lost from our bodies does turn out to be around 8 cups a day, you don’t need to replace all of it with plain old water. We get water replacement from fruits, vegetables, and other beverages such as milk, tea, soda, and yes, even coffee! However, water is the best fluid for boosting body fluids because it is absorbed the fastest of all the fluids!

Beth Kitchin MS RD
Assistant Professor, Nutrtion Sciences
University of Alabama at Birmingham