To guard against an increasingly common
exercise-associated condition, athletes should be warned
about the risk of drinking too much fluid, and athletes
and coaches should be better educated about the signs
and symptoms of exercise-associated hyponatremia (EAH),
according to a new consensus statement.
"The incidence of EAH is increasing at an alarming rate
and is arguably the most prevalent serious medical
condition encountered by endurance athletes over the
past decade," Dr. Tamara Hew-Bulter, of the University
of Cape Town in South Africa told Reuters Health. "We
wish to draw attention to the morbid medical
complications associated with drinking too much fluid,
which are dire and have caused death."
Hew-Bulter and other members of Exercise-Associated
Hyponatremia Consensus Panel reviewed available research
in an effort to provide reliable information on the
topic to health professionals and the general public.
The consensus statement was published in the Clinical
Journal of Sport Medicine.
Exercise-associated hyponatremia occurs when sodium
levels in the blood drop below normal levels, or about
135 mmol/liter, in most cases. The condition is most
commonly associated with physical activity lasting more
than four hours.
Many early signs and symptoms of the condition are
similar to those for dehydration, and include nausea,
vomiting, headache and bloating. As hyponatremia
progresses, signs can include altered mental status,
such as confusion and disorientation, seizures,
respiratory distress, coma and even death.
Published research shows that the best way to avoid the
condition is to refrain from drinking excessive amounts
of fluid - water or sports drinks - while exercising. In
fact, limiting the availability of fluids during races,
with aid stations placed at every five kilometers,
rather than smaller distances during a standard
marathon, for example, has been shown effective in
reducing the incidence of the condition.
Also, Hew-Bulter and her colleagues note, medical
facilities at endurance events should be equipped to
analyze athletes' sodium levels and to provide
appropriate treatment if they fall below normal limits.
Hew-Bulter considers exercise-associated hyponatremia
more dangerous than dehydration, which is "more of a
detriment to performance than it is to health." However,
she stresses that "the EAH Consensus panel is not
recommending that athletes refrain from drinking during
exercise."
"We aim to encourage athletes to shoot for a middle
ground in regards to drinking habits and rely on their
body's internal cues rather than heed fixed fluid
guidelines that cannot account for the wide variety of
sports and athletes that are competing in endurance
activities in a variety of climates," she added.
Commenting on the consensus statement, Dr. W. Larry
Kenney, a Penn State University-based expert on
hydration and related issues, said that
exercise-associated hyponatremia is a very serious, but
"an extremely rare phenomenon."
It is "far less common than serious dehydration," he
told Reuters Health. To avoid experiencing either
condition, however, the "idea is still to consume fluids
to try to match sweating loss," he said.
"We want to encourage athletes not to go to either
extreme - not to over drink and not to under drink
during exercise," said Kenney.
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References:
worldhealth.net
Reuters Health and Clinical Journal of Sport Medicine
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