Nearly half of runners may be drinking too much during races
(Medical Xpress) -- Nearly half of recreational runners may be drinking too much fluid during races, according to a survey of runners by Loyola University Health System researchers.
Expert guidelines recommend runners drink only when thirsty. But the Loyola survey found that 36.5 percent of runners drink according to a preset schedule or to maintain a certain body weight and 8.9 percent drink as much as possible.
Nearly one-third of runners (29.6 percent) incorrectly believe they need to ingest extra salt while running. And more than half (57.6 percent) say they drink sports drinks because the drinks have electrolytes that prevent low blood sodium. In fact, the main cause of low sodium in runners is drinking too much water or sports drinks.
"Many athletes hold unscientific views regarding the benefits of different hydration practices," researchers concluded. The study was published in the June 2011 issue of the British Journal of Sports Medicine.
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 Dr. James Winger, first author of the study.
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 and coma.
In recent years, there have been 12 documented and 8 suspected runners' deaths from hyponatremia, said Loyola exercise physiologist Lara Dugas, Ph.D., a co-author of the study.
The International Marathon Medical Directors Association recommends that runners drink only when thirsty.
The Loyola researchers surveyed 197 runners who competed in the 2009 Westchester, Ill., Veterans Day 10K and 5K runs and two other runs on Chicago's lakefront. The 91 male runners, on average, had been running for 13 years and had run an average of 1.9 10K races and 0.9 marathons. The 106 women, on average, had been running 8.3 years and had run an average of 1.3 10K races and 0.7 marathons.
In the survey, the runners generally said advertising by sports drink manufacturers had little or no influence on their beliefs. But the behaviors of many of the runners indicate otherwise.
During the 1980s and 1990s, sports drinks ads warned about the supposed dangers of dehydration and recommended that runners drink as much as 1.2 liters (five cups) per hour. Sports drink manufacturers generally have stopped promoting overdrinking. But the unscientific beliefs persist that runners should drink as much as they can or according to a preset schedule.
"We have been trained to believe that dehydration is a complication of endurance exercise," Dugas said. "But, in fact, the normal physiological response to exercise is to lose a small amount of fluid. Runners should expect to lose several pounds during runs, and not be alarmed."
Provided by Loyola University Health System
- Scientist warns marathon runners: Water won't help you keep your cool Apr 22, 2007 | not rated yet | 0
- Runners -- Let thirst be your guide Jun 16, 2007 | not rated yet | 0
- Probing Question: Are sports drinks better than water for athletes? May 11, 2007 | not rated yet | 0
- Runners a marathon a net benefit for the body, experts say Jan 23, 2009 | not rated yet | 0
- Chocolate milk is a 'natural' for post-exercise recovery Jun 02, 2010 | not rated yet | 0
- Motion perception revisited: High Phi effect challenges established motion perception assumptions Apr 23, 2013 | 3 / 5 (2) | 2
- Anything you can do I can do better: Neuromolecular foundations of the superiority illusion (Update) Apr 02, 2013 | 4.5 / 5 (11) | 5
- The visual system as economist: Neural resource allocation in visual adaptation Mar 30, 2013 | 5 / 5 (2) | 9
- Separate lives: Neuronal and organismal lifespans decoupled Mar 27, 2013 | 4.9 / 5 (8) | 0
- Sizing things up: The evolutionary neurobiology of scale invariance Feb 28, 2013 | 4.8 / 5 (10) | 14
Classical and Quantum Mechanics via Lie algebras
Apr 15, 2011 I'd like to open a discussion thread for version 2 of the draft of my book ''Classical and Quantum Mechanics via Lie algebras'', available online at http://lanl.arxiv.org/abs/0810.1019 , and for the...
- More from Physics Forums - Independent Research
More news stories
The Senate has overwhelmingly rejected an amendment allowing states to require labeling of genetically modified foods.
Health 25 minutes ago | not rated yet | 0
(AP)—McDonald's once again faced criticism that it's a purveyor of junk food that markets to children at its annual shareholder meeting Thursday.
Health 1 hour ago | not rated yet | 0
Can economic incentives such as gift cards, T-shirts, and time off from work motivate members of the public to increase their donations of blood?
Health 3 hours ago | not rated yet | 0 |
Family caregivers of older adults with dementia are less stressed and their moods are improved on days when dementia patients receive adult day services (ADS), according to Penn State researchers.
Health 5 hours ago | not rated yet | 0
Given the implications for the overall health, development, and academic success of children, schools should play a primary role in ensuring that all students have opportunities to engage in at least 60 minutes per day of ...
Health 5 hours ago | not rated yet | 0
Even while being dragged to its destruction inside a cell, a cancer-promoting growth factor receptor fires away, sending signals that thwart the development of tumor-suppressing microRNAs (miRNAs) before it's dissolved, researchers ...
45 minutes ago | not rated yet | 0 |
Ethnic background plays a surprisingly large role in how diabetes develops on a cellular level, according to two new studies led by researchers at the Stanford University School of Medicine.
1 hour ago | not rated yet | 0 |
Finnish researchers unveiled new data Thursday to link the Pandemrix flu vaccine to a higher risk of the sleeping disorder narcolepsy in adults.
45 minutes ago | not rated yet | 0
Maintaining a heart healthy lifestyle may also help protect chronic kidney disease patients from developing kidney failure and dying prematurely, according to a study appearing in an upcoming issue of the Journal of the Am ...
15 minutes ago | not rated yet | 0
(AP)—Johnson & Johnson is developing what could eventually be game-changing treatments for depression and pain, and it's aiming to apply for approval of more than 10 new medicines by 2017, executives said Thursday during ...
35 minutes ago | not rated yet | 0
A second child has contracted polio in a restive Pakistani tribal region near the Afghan border after the Taliban banned vaccinations there nearly a year ago, a UN official said Thursday.
1 hour ago | not rated yet | 0