Featured Research

from universities, journals, and other organizations

Danger In Marathon Runners Drinking Too Much Water

Date:
May 5, 2000
Source:
University Of California At San Francisco
Summary:
Drinking too much water while running a marathon can kill you. That may sound like a rumor passed around on the Internet, but it does happen in some cases. Now researchers at the University of California, San Francisco think they know why. The excess water can help to cause the brain to swell, and fluid to leak into the lungs, either of which can be fatal.

Drinking too much water while running a marathon can kill you. That may sound like a rumor passed around on the Internet, but it does happen in some cases.

Related Articles


Now researchers at the University of California, San Francisco think they know why. The excess water can help to cause the brain to swell, and fluid to leak into the lungs, either of which can be fatal. They confirm that the cure is a simple intravenous dose of salt water.

The findings are published in the May 2 issue of the Archives of Internal Medicine.

Although marathon runners need to keep hydrated, in the last decade physicians have come to realize that a few hours of sweating away water and salt, but drinking only water, could put some runners into a danger zone known as hyponatremia. It was found that some runners who collapsed and died during a marathon had lost the normally well-balanced ratios of salt and water - they had plenty of water, but far too little salt.

To understand how this might kill some runners, Allen Arieff, MD, a UCSF professor of medicine at the Veterans Affairs Medical Center in San Francisco, and two colleagues at Baylor College of Medicine, treated, or consulted on the cases of, seven athletes who suffered hyponatremia while running a marathon. They had all been nauseous, vomiting, or confused at some point during their run. Six of the seven patients survived after intravenous treatment with a high salt solution.

All the patients share several characteristics, which provide clues about the mechanisms of hyponatremia, Arieff said. In addition to having fluid in their lungs - a hallmark of hyponatremia - the patients all had low levels of sodium and oxygen in their blood. X-rays of six of the patients showed that they had significant brain swelling.

In the study, Arieff suggests the following mechanism. The body, in an attempt to keep a balance of salt and water levels between the blood and tissues, begins to draw water out of the blood, leading to puffiness in the skin and swelling in the brain. The brain responds to the pressure by sending an emergency distress call to release water into the lungs. The lung fluid, or the brain pressure, eventually kills most patients with hyponatremia, Arieff said. "They either suffocate or their brain herniates," he said.

All the patients in this study had been taking ibuprofen-based pain relievers, such as Advil, which can make the body retain even more water. "These drugs could make (hyponatremia) more likely, and could make it more severe," Arieff said. However, he added that this apparent correlation needs to be confirmed in a larger study.

Women are likely to be more at risk for hyponatremia, Arieff said, because the female hormone estrogen can act in combination with another hormone called anti-diuretic hormone (ADH) to constrict the blood vessels in the brain. ADH is produced to save water in response to heavy perspiration.

In preparation for this year's marathon season, emergency room physicians should be educated about hyponatremia, and how to treat it, Arieff said. Most collapsed runners admitted to the emergency room would be thought to suffer from heart disease, so doctors might not suspect hyponatremia, especially since heart failure causes similar symptoms. But if they know to look for it by measuring blood sodium levels and giving a chest X-ray, doctors will be able to treat most cases of hyponatremia successfully, with a simple intravenous dose of high salt solution. Diagnosis is critical, Arieff said, because "most of these patients won't survive if they are treated for heart failure."

To avoid hyponatremia, Arieff recommends that athletes take salt tablets with their water before, and even during, marathons or longer endurance events. It' s also possible that sports drinks containing electrolytes could help, he said. And, of course, it's important to drink water during a race, but only enough to replenish what is lost through perspiration.

Arieff's co-author's on the study were J. Carlos Ayus, MD, a professor of medicine, and Joseph Varon, MD, an assistant professor of medicine, both at Baylor College of Medicine in Houston.


Story Source:

The above story is based on materials provided by University Of California At San Francisco. Note: Materials may be edited for content and length.


Cite This Page:

University Of California At San Francisco. "Danger In Marathon Runners Drinking Too Much Water." ScienceDaily. ScienceDaily, 5 May 2000. <www.sciencedaily.com/releases/2000/05/000503183723.htm>.
University Of California At San Francisco. (2000, May 5). Danger In Marathon Runners Drinking Too Much Water. ScienceDaily. Retrieved October 24, 2014 from www.sciencedaily.com/releases/2000/05/000503183723.htm
University Of California At San Francisco. "Danger In Marathon Runners Drinking Too Much Water." ScienceDaily. www.sciencedaily.com/releases/2000/05/000503183723.htm (accessed October 24, 2014).

Share This



More Health & Medicine News

Friday, October 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

IKEA Desk Converts From Standing to Sitting With One Button

IKEA Desk Converts From Standing to Sitting With One Button

Buzz60 (Oct. 24, 2014) IKEA is out with a new convertible desk that can convert from a sitting desk to a standing one with just the push of a button. Jen Markham explains. Video provided by Buzz60
Powered by NewsLook.com
Ebola Protective Suits Being Made in China

Ebola Protective Suits Being Made in China

AFP (Oct. 24, 2014) A factory in China is busy making Ebola protective suits for healthcare workers and others fighting the spread of the virus. Duration: 00:38 Video provided by AFP
Powered by NewsLook.com
WHO: Millions of Ebola Vaccine Doses by 2015

WHO: Millions of Ebola Vaccine Doses by 2015

AP (Oct. 24, 2014) The World Health Organization said on Friday that millions of doses of two experimental Ebola vaccines could be ready for use in 2015 and five more experimental vaccines would start being tested in March. (Oct. 24) Video provided by AP
Powered by NewsLook.com
Doctor in NYC Quarantined With Ebola

Doctor in NYC Quarantined With Ebola

AP (Oct. 24, 2014) An emergency room doctor who recently returned to the city after treating Ebola patients in West Africa has tested positive for the virus. He's quarantined in a hospital. (Oct. 24) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins