Featured Research

from universities, journals, and other organizations

Scientist Warns Marathon Runners: Water Won't Help You Keep Your Cool

Date:
April 23, 2007
Source:
University of Exeter
Summary:
A research team led by the University of Exeter has found that fluid intake does not affect body temperature in runners. Therefore, runners in today's London Marathon will not improve their performance by drinking more water.

Runners in the recent London Marathon may be tempted to down several litres of water to keep their cool and achieve their best time, but large fluid intake does not achieve either, according to a sports scientist from the University of Exeter.

Related Articles


With the Marathon's temperatures reaching 19 degrees Celsius, the average runner will potentially lose almost a litre of sweat every hour and reach a body temperature of over 39 degrees, two degrees above normal. The sporting community has long assumed that drinking large amounts of water helps to keep the body's temperature down, which improves performance. A recent study led by Dr Chris Byrne of the University of Exeter shows that the level of fluid intake has absolutely no effect on body temperature or performance.

Dr Chris Byrne, sport scientist from the University of Exeter said: 'We'll see many of today's Marathon runners clutching bottles of water. The conventional view among both scientists and the fitness media is that fully replacing sweat losses by fluid intake during exercise will reduce an athlete's body temperature and improve performance. Our research, which for the first time measured internal body temperature continuously during an actual race, revealed no evidence that fluid intake makes runners cooler or improves performance.'

Dr Byrne and his team monitored a group of male runners taking part in the Singapore Army Half-Marathon, a 21km race that took place in temperatures between 26 and 29 degrees Celsius and 75-90% relative humidity. The night before the race, the runners ingested telemetric temperature sensors, which contain temperature-sensitive quartz crystal oscillators that vibrate at a frequency relative to its surrounding temperature and communicate the temperature by radio wave to a recording device worn by the runner. For previous studies, body temperatures have been taken after races, but this was the first time that researchers have monitored body temperatures continuously throughout a race.

Over half the runners reached body temperatures exceeding 40 degrees and all lost an average of 1.5 litres of sweat per hour. Runners replaced between 6% and 73% of their sweat losses during the race. There was no relationship between the amount of fluid each runner consumed, his body temperature and overall performance in the race. The highest body temperature observed (41.7C) was recorded from a runner replacing the greatest amount of his sweat losses (73%) and therefore being the least dehydrated of the study sample.

Dr Byrne concludes: 'I would encourage those people taking part in today's Marathon to be well hydrated before the race, but not to feel they need to drink water throughout the event. Listen to your body and drink if you feel thirsty, but drinking several litres of water will not help you run any faster.'

The original study was published in the journal Medicine & Science in Sports & Exercise, which is published by the American College of Sports Medicine.


Story Source:

The above story is based on materials provided by University of Exeter. Note: Materials may be edited for content and length.


Cite This Page:

University of Exeter. "Scientist Warns Marathon Runners: Water Won't Help You Keep Your Cool." ScienceDaily. ScienceDaily, 23 April 2007. <www.sciencedaily.com/releases/2007/04/070421202623.htm>.
University of Exeter. (2007, April 23). Scientist Warns Marathon Runners: Water Won't Help You Keep Your Cool. ScienceDaily. Retrieved October 23, 2014 from www.sciencedaily.com/releases/2007/04/070421202623.htm
University of Exeter. "Scientist Warns Marathon Runners: Water Won't Help You Keep Your Cool." ScienceDaily. www.sciencedaily.com/releases/2007/04/070421202623.htm (accessed October 23, 2014).

Share This



More Health & Medicine News

Thursday, October 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Ebola Fears Keep Guinea Hospitals Empty

Ebola Fears Keep Guinea Hospitals Empty

AP (Oct. 23, 2014) Fears of Ebola are keeping doctors and patients alike away from hospitals in the West African nation of Guinea. (Oct. 23) Video provided by AP
Powered by NewsLook.com
Orthodontist Mom Jennifer Salzer on the Best Time for Braces

Orthodontist Mom Jennifer Salzer on the Best Time for Braces

Working Mother (Oct. 22, 2014) Is your child ready? Video provided by Working Mother
Powered by NewsLook.com
U.S. Issues Ebola Travel Restrictions, Are Visa Bans Next?

U.S. Issues Ebola Travel Restrictions, Are Visa Bans Next?

Newsy (Oct. 22, 2014) Now that the U.S. is restricting travel from West Africa, some are dropping questions about a travel ban and instead asking about visa bans. Video provided by Newsy
Powered by NewsLook.com
More People Diagnosed With TB In 2013, But There's Good News

More People Diagnosed With TB In 2013, But There's Good News

Newsy (Oct. 22, 2014) The World Health Organizations says TB numbers rose in 2013, but it's partly due to better detection and more survivors. Video provided by Newsy
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