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 March 29, 2015 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 March 29, 2015).

Share This


More From ScienceDaily



More Health & Medicine News

Sunday, March 29, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

S. Leone in New Anti-Ebola Lockdown

S. Leone in New Anti-Ebola Lockdown

AFP (Mar. 28, 2015) — Sierra Leone imposed a three-day nationwide lockdown Friday for the second time in six months in a bid to prevent a resurgence of the deadly Ebola virus. Duration: 01:17 Video provided by AFP
Powered by NewsLook.com
These Popular Antibiotics Can Cause Permanent Nerve Damage

These Popular Antibiotics Can Cause Permanent Nerve Damage

Newsy (Mar. 27, 2015) — A popular class of antibiotic can leave patients in severe pain and even result in permanent nerve damage. Video provided by Newsy
Powered by NewsLook.com
WH Plan to Fight Antibiotic-Resistant Germs

WH Plan to Fight Antibiotic-Resistant Germs

AP (Mar. 27, 2015) — The White House on Friday announced a five-year plan to fight the threat posed by antibiotic-resistant bacteria amid fears that once-treatable germs could become deadly. (March 27) Video provided by AP
Powered by NewsLook.com
House Ready to Pass Medicare Doc Bill

House Ready to Pass Medicare Doc Bill

AP (Mar. 26, 2015) — In rare bipartisan harmony, congressional leaders pushed a $214 billion bill permanently blocking physician Medicare cuts toward House passage Thursday, moving lawmakers closer to resolving a problem that has plagued them for years. (March 26) 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