Last year the runners and fans of the Boston Marathon were stunned to learn of the death of a runner from hyponatremia: 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 over-consume 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 3-5 mile run.  But longer races, like the Boston Marathon, can create an electrolyte deficiency over time that has confounding symptoms that are completely counter-intuitive.

“In short,“ says Ghiron, “if you are over-consuming water and under-consuming 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, over-hydration and dehydration 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, 5 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 10-25 grams a day of salt pre race.”

Training to avoid hyponatremia: