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home > community > viewpoint > hyponatremia a concern for marathon runners

Hyponatremia a Concern for Marathon Runners
Runners are well aware of the dangers of dehydration, but there's been too little public education about the danger of over hydration, which is just as dangerous.

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By Karen Ghiron
Posted Thursday, 17 April, 2003

Runners are well aware of the dangers of dehydration, but there's been too little public education about the danger of over hydration, which is just as dangerous," says Karen Ghiron of Wellness Works in Newton. Ghiron is a fitness trainer and coach for athletes training for endurance events such as marathons, Triathlons, and Iron Man competitions.

Last year the runners and fans of the Boston Marathon were stunned to learn of the death of a runner from hyponatremia: a condition often resulting from over hydration, which depletes essential minerals from the body, causing disorientation, illness and in rare cases, death.

As the 107th Boston Marathon runners step up to the starting line on April 21, they and their support teams need to know about this serious condition, how to avoid it, and how to recognize it in time to get help.

"Long distance, marathon and triathlon runners are most at risk," says Ghiron, "because the longer they run the more they sweat, and the more likely they are to consume too much water without taking in enough sodium." Sodium (salt and chloride) is an essential electrolyte which allows water to permeate the cell walls so that water can be redistributed throughout the body, allowing muscles to work and organs to function.

Most people don't get into trouble with a morning workout or a three to five-mile run. But longer races, like the Boston Marathon, can create an electrolyte deficiency over time that can result in confounding symptoms that are completely counter-intuitive. "In short, " says Ghiron, "if you are consuming too much water and not enough electrolytes, your body can't use the water you've given it, and you'll actually be dehydrated while you're virtually drowning your body. " Untreated, this can lead to collapse, convulsions, and even death.

The symptoms of hyponatremia include bloating, a feeling of fullness in your stomach, nausea, incoherence and disorientation. You may be unable to take in any more water, and also unable to urinate: these are warning signs to get to the medical tent and ask for help. "It's important to review the symptoms and signs with your support team," says Ghiron, "because if you have the symptoms of hyponatremia, chances are good that you'll either be unable to communicate that, or unable to know you're in trouble."

Ghiron stresses that it's important to share this information with your support team and other runners, because "if you're confused and disoriented, you may not know you're in trouble, so be sure to review the signs with your support team well in advance."

"Even seasoned athletes can learn something new," Ghiron says, and she has some first-hand experience with hyponatremia. While cycling in the Pan Mass Challenge in 1997, Ghiron's focus was fixed on keeping adequately hydrated and keeping her eye on the finish. A seasoned athlete with 14 races, five Boston Marathons and several Ironman competitions under her belt, she reached the finishing line in an exhausted, disoriented state that baffled and frightened her, and was a mystery to her support team. "I was dizzy and confused, and I felt weirdly out of control. My stomach felt too full, and I literally couldn't take in any more water without being sick. I didn't know then that I needed to get to the medical tent quick, and I'm lucky I got through it. "

Now Ghiron trains her clients to be aware of the possibility of hyponatremia and the importance of including sodium replacement as a standard preventive step in training.

Good prevention begins with training in advance. "As part of your routine, " Ghiron says, "learn to balance the amount of water you consume with the rate at which you sweat. Practice taking in small amounts of water at a time, and getting salt in fluids, and notice how your body reacts. Train in a hot environment if you can, to get a better sense of how you react to heat over time. As a general rule, try to take in one gram of sodium per hour during a long event, and build up your sodium reserves by taking 10 to 25 grams a day of salt pre-race."

Training to avoid hyponatremia:

  • Drink small amounts of fluids to stay hydrated, but don't overdose on water.
  • Take in electrolytes through sports drinks which have sodium and potassium.
  • Ask the race director what fluids will be given on race day.
  • Try to eat snack foods with salt, like pretzels or chips.
  • Alternate water and hot clear chicken broth to get both water and salt.
  • Tomato-based drinks include high sodium content.
  • Salt tablets should not be used unless you have used them before, know a safe dosage and know how you tolerate them.
  • Avoid taking aspirin, acetaminophen or ibuprofen during the race, as it may affect kidney function.

Precautions on race day

  • Make sure you eat and drink a good breakfast, one that you body is familiar with. The race doesn't begin until 12:00 Noon. That makes for a very long day if you haven't eaten.
  • Bring a snack pack, including an energy bar, banana, or an orange with you to eat a half-hour before the race, to ensure you don't start out with a potassium deficit.
  • Carry a water bottle or fuel belt with you during the race.
  • Pack some pretzels, crackers of other salty food with you.
  • Drink sports drinks with electrolytes along the way.
  • If you find your stomach feels too full, you can't take in more water and you don't feel well, get to the medical tent right away.

"Good luck and realistic training will serve you well on race day," says Ghiron. "And remember that proper training includes learning how to replace sodium and balance your water intake!"

Karen Ghiron is a certified Fitness Consultant and trainer with a BS in Exercise Science. She owns Wellness Works in Newton, offering in-home training for athletes and people interested in fitness. She has run 14 marathons, including races in London, Marine Corps, and New York City, and has run the Boston Marathon five times. She has also raced in Ironman competitions in Canada, New Zealand and the USA. As a trainer, Karen believes education and preparation are as important as training and performance, and is committed to helping people reach reasonable and challenging goals. She can be reached at 617-965-6585 or at for more information.



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