do runners overhydrate on race day?

by Sandy Todd Webster on Oct 17, 2011

Food for Thought

About half of you and your clients may be drinking too much fluid during running races, say results of a recent survey by Loyola University Health System researchers, published in the June 2011 issue of the British Journal of Sports Medicine. The survey revealed the following about runners:

  • While expert guidelines recommend that runners drink only when thirsty, 36.5% of runners reported that they drink according to a preset schedule or to maintain a certain body weight.
  • Of those surveyed, 8.9% said they drink as much as possible.
  • Nearly a third of runners (29.6%) incorrectly believe they need to ingest extra salt while running.
  • More than half (57.6%) said they drink sports drinks because they provide electrolytes that prevent low blood sodium. In fact, the main cause of low sodium in runners is drinking too much water or sports drink.

“Many athletes hold unscientific views regarding the benefits of different hydration practices,” researchers concluded. Drinking too much fluid while running can cause a potentially fatal condition called exercise-associated hyponatremia. It occurs when runners drink even when they are not thirsty. Drinking too much during exercise can dilute the sodium content of blood to abnormally low levels.

Drinking only when thirsty will prevent overconsumption of fluids. “It’s the safest known way to hydrate during endurance exercise,” said Loyola sports medicine physician James Winger, MD, lead author of the study, in a press release.

Symptoms of hyponatremia can include nausea, vomiting, headache, confusion, loss of energy, muscle weakness, spasms or cramps. In extreme cases, the condition can lead to seizures, unconsciousness, coma and even death.

For a closer look at overhydration, read “Hyponatremia: The Other Side of the Hydration Story” in the September 2005 issue of IDEA Fitness Journal:

IDEA Fitness Journal, Volume 8, Issue 11

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About the Author

Sandy Todd Webster

Sandy Todd Webster IDEA Author/Presenter

Sandy Todd Webster is Editor in Chief of IDEA's publications, including the award-winning IDEA FITNESS JOURNAL, the health and fitness industry's leading resource for fitness and wellness professionals worldwide. Sandy joined IDEA in 2001 as executive editor of IDEA PERSONAL TRAINER and IDEA FITNESS MANAGER magazines and was promoted to lead the editorial team in 2003. More than 20 years in magazine publishing, marketing communications and creative services have shaped her straightforward approach to multi-channel communication. Early experience in Los Angeles as a sports writer/reporter, and then enriching years as a managing editor in allied health care publishing have pulled her across a spectrum of stimulating subject matter. Fitness, health and nutrition reside at the perfect center of this content continuum, she feels. A Chicago native, Sandy grew up fully engaged in various competitive sports. Her drive and dedication as an athlete translate to a disciplined work ethic and unwavering appro