Do you really need 8 glasses of water a day?(part 2)

Don't overdo it

The debate about how much water we really need to be drinking is centered around the risk of hyponatremia, or taking in more fluid that the body loses while sweating. It is a serious condition that occurs when there is not enough sodium (or salt) in the body fluids outside of the cells. This can cause swelling, including of the brain. Hyponatremia happens when a person sweats excessively in one stint, does not eat, does not urinate enough, and drinks a great deal of water. Symptoms include confusion, headaches, muscle spasms, vomiting, convulsions, and fatigue. In the worst cases, hyponatremia can lead to seizures, coma, and even death.

There are exceptions for medical conditions and other situations, but athletes are often watched for signs of hyponatremia, especially those participating in endurance events like a marathon or triathlon.

Experts advise taking in some electrolyte-replacement fluids in addition to drinking water while you are exercising. However, you really only need a minimal amount to keep your body in balance and give you an energy kick. For example, it is recommended that runners out for 30 minutes to an hour take in three to six ounces of fluid every 15 or 20 minutes, including one sports drink. There's also evidence that simply taking sips or swishing a sports drink will do the trick.

Don't get sucked in to the sports drink hype

The risks of hyponatremia are steep, but take the hype about over-hydrating with a grain of salt. The multi-billion-dollar sports drink industry has pushed the idea that most people need more than water when they are active. However, some experts say that most people don't need a lot of sports beverages, and that they often just add calories to diets. The CDC recommends choosing sports drinks that do not have added sugar, which can total 38 grams in just one bottle.

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In May, the American Academy of Pediatrics issued a report warning that children should not consume sports drinks except when participating in lengthy sports competitions.

Consider these other drinks that carry the same benefits of electrolyte-replacement beverages but also have nutritional value or are less caloric:

•Chocolate milk beat out water, sports drinks and regular milk in a recent study of what is the best post-exercise drink for our bodies. Lowfat milk has also been touted as an ideal remedy for muscles that have been rigorously exercised.

•Coconut water is a nonfat beverage that has about half the calories of a sports drink while being high in potassium and antioxidants. Coconut water works best for average athletes.

•Pickle juice is packed with sodium and, if you can bear it, can be added to water or made into popsicles for hot-weather workouts. There's also scientific and anecdotal evidence that drinking a shot out of the pickle jar will help alleviate muscle cramps faster.

•Beetroot juice has recently been recognized as a new "super drink" after one study found it helped competitive cyclists cut down their times by a few critical seconds. Not taking part in the Tour de France? Then keep an eye out for more research on how this alternative beverage might help weekend warriors.