National group warns about drinking too much water

BY DAVID QUICK Of The Post and Courier Staff

Story last updated at 7:13 a.m. Tuesday, May 13, 2003

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Following the nutrition and health news can be frustrating.

Studies discover this. Follow-up studies dispel that. Then there are the studies performed by a certain industry that support the product of that industry as the fountain of youth. Various diets have gurus, proponents and dissenters that leave us with no clear idea of what's good or bad.

Runners, for example, often have to decide between following the low-carbohydrate diet, espoused by disciples of the late Dr. Robert Atkins, to stay light on their toes, or to eat carbs that are needed to fuel miles and miles of pounding the pavement.

Now comes what I think may be the next big controversy: to drink or not to drink (water, that is).

USA Track & Field -- the national governing body for track and field, long-distance running and race walking -- announced in Boston last month that it is changing its guidelines for "hydrating" during races.

"For athletes in general and especially for those completing a marathon in more than four hours, USATF recommends consuming 100 percent of fluids lost due to sweat while racing," according to its Web site. "This marks a significant change from the understanding most runners have that they should be drinking as much as possible and following the guideline to 'stay ahead of your thirst,' which has been held as the standard recommendation for many years ... Simply put, runners should be sensitive to the onset of thirst as the signal to drink, rather than staying ahead of thirst."

The change comes as more attention is being given to the risk of hyponatremia, or low levels of sodium and potassium in the bloodstream.

It's a dangerous condition that is being seen more as runners who drink too much water and subsequently drain their bodies of sodium and potassium. Severe cases may involve grand mal seizures, increased intra-cranial pressure, pulmonary edema (fluid in the lungs), respiratory arrest and even death, and typically occur in continuous physical activities lasting more than four hours.

USATF says the change not only reflects a scientific rethinking of proper hydration, but also the changes in average finishing times of marathon fields.

"The 'new running boom' has seen more mid-pack and back-of-the-pack runners taking up marathoning," USATF CEO Craig Masback said, a reference to those who are generally slow marathoners, finishing between four hours and seven hours.

The USATF's new hydration guideline is going to require a little science by each runner. The organization is advising runners to consume one liter of fluid for every liter lost during a race, so runners now have to determine their rate of sweat loss weeks before a race. (Runners can determine their rate of sweat loss weeks before a race by using the USATF Self-Testing Program for Optimal Hydration, as described on www.usatf.org.)

HYPE OR HARM?

Most runners who read about their sport likely have known about hyponatremia for a few years and/or are well aware of the general need to include electrolytes, a term for sodium and potassium, in their fluid consumption while training and racing.

Many sports drinks, such as long-time classic Gatorade, have electrolytes, as do many of the energy gels that should be consumed with water. Many "runner" foods, such as bananas, orange juice and salty pretzels, also will help.

Water, hopefully, won't be demonized by the various interpretations of the USATF's official stance. (A Monday New York Times article on the subject was titled "New Advice to Runners: Don't Drink the Water.")

Expect more critiques of water consumption this summer.

Last month's USATF announcement comes on the heels of an article published in the November edition of The American Journal of Physiology, which stated there was no scientific support for healthy adults to drink at least eight glasses of water a day. Other papers state that dehydration is not as much of a concern as other conditions produced by long periods of exertion.

Those conditions include hyperthermia and hypotension, which have little to do with dehydration, according to the Times article.

Hyperthermia (heat illness) occurs when a runner pushes himself or herself too hard in especially hot or humid conditions. Hypotension, which can cause a faint feeling, results from a runner stopping suddenly after a significant run. Blood pools in the legs and a decent flow doesn't get to the rest of the body. Propping the legs up for a few minutes is the easy cure.

All this information is great. Hopefully, as the academics earn credit points with their various research papers and the information hits the streets, we runners won't forget that fluids, including water, are still important. Remember the simple rule of hydration comes down this observation: having clear urine means you are hydrated and ready to run.

At least until a new study says otherwise.