2 minute read
Coaches Must be Aware of Exercise-Associated Hyponatremia
Exercise-associated hyponatremia is believed to affect approximately 15% of runners and triathletes at major competitions and in severe cases has been the cause of several fatalities. All coaches, especially those working with distance athletes, must be aware of the warning signs.
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What is it?
Athletes who drink excessive amounts of fluids during prolonged exercise - particularly novice marathon runners - can develop dangerously low sodium levels, called Exercise-Associated Hyponatremia (EAH)" (Hew-Butler et al., 2015). EAH occurs when excessive fluid dilutes the body's sodium level resulting in the inability to perform normal regulatory processes.
What should the coach be looking out for?
It is critical that coaches understand the causes and are able to recognise when their runners may be experiencing EAH. Although mild cases of EAH may have no symptoms, when more severe it can lead to bloating, nausea, headaches and puffiness in the face. If not treated promptly EAH can result in breathing difficulties, seizures or even death due to the swelling of the brain.
Who is at risk?
Everyone has the potential to suffer from EAH and it is believed to affect as many as 2% to 7% of participants of an average open-entry marathon. (Rosner, 2015). Female runners with a low body mass index are especially at risk. Novice marathon runners slower than four hours have been shown to have a higher likelihood of suffering from EAH than experienced runners.
Environment also plays a signifcant role in increasing the risk factor. Races held in extreme hot conditions increase the chances of athletes developing EAH, believed to be caused by pre-race overhydration in anticipation of sweating during the race.
What do you do if your runner shows symptoms of EAH?
If you suspect your runner is suffering from EAH seek immediate medical treatment. In most cases, close monitoring and fluid restriction is enough for recovery, but severe cases can quickly result in mortality without the appropriate treatment. Doctors may prescribe a hypertonic saline to recover sodium levels in the affected runner.
How do you prevent EAH?
By reading this article you are already in a great position to prevent EAH affecting your runners. Awareness of the dangers of consuming too much water is one of the most effective preventions. Educate your runners of the potential risks and encourage them to avoid overhydration, especially pre-race overhydration.
Most races will ensure that hydration stations are adequately spaced out to help prevent EAH but if not, plan with your runners in advance where they should be taking fluids on the route.
The Debate: When Should you Drink?
At the current time there is no consensus between peak bodies for the best practice regarding how much is the right amount to drink. The Third International Exercise-Associatted Hyponatremia Consensus Development Conference (2015) stated that "thirst should provide adequate stimulus for preventing excess dehydration." This contradicts the position of the American College of Sports Medicine (1996) who stated that individuals should "start drinking early and at regular intervals...consume the maximal amount that can be tolerated."
Coaches are encouraged to assess the evidence for themselves and regardless of which side of the argument you agree with, ensure that you are fully aware of the symptoms of EAH to protect the health and well-being of your runners.
