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 (41.7°C) 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 26, 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 26, 2014).

Share This



More Health & Medicine News

Sunday, October 26, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Texas Nurse Nina Pham Cured of Ebola

Texas Nurse Nina Pham Cured of Ebola

AFP (Oct. 25, 2014) — An American nurse who contracted Ebola while caring for a Liberian patient in Texas has been declared free of the virus and will leave the hospital. Duration: 01:01 Video provided by AFP
Powered by NewsLook.com
Toxin-Packed Stem Cells Used To Kill Cancer

Toxin-Packed Stem Cells Used To Kill Cancer

Newsy (Oct. 25, 2014) — A Harvard University Research Team created genetically engineered stem cells that are able to kill cancer cells, while leaving other cells unharmed. Video provided by Newsy
Powered by NewsLook.com
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

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