April 14, 2005
"I've heard of being dehydrated, but never of drinking too much water," admitted race volunteer Anne Kronk.
Most people, including the doctors who treated physical therapist Jay Dicharry after his Iron Man race, are not aware that drinking too much water can be deadly.
"My friend noticed that I was having a neurological symptom, which was that my eye was twitching. So he took me to the medical tent. I was misdiagnosed with dehydration and I woke up from my coma five days later," recalled Dicharry.
As with most athletic events, especially endurance ones, people run the risk of being dehydrated, but according to a recent study of about five hundred Boston Marathon runners, more than one in eight of the competitors were over-hydrated. This leads to a condition called hyponatremia, which is a sodium imbalance.
"When sodium decreases, cell volume tends to expand enormously. This causes cells to swell," explained Dicharry.
Sodium regulates the body's homeostasis state. Drinking too much water dilutes the sodium. This can be very dangerous, and even fatal.
"This can lead to seizure. This can lead to overheating, can lead to brain damage, can lead to coma, and can even lead to death," said Dicharry.
Those active for over four hours are the ones in danger of hyponatremia. Dicharry said that someone running a mile as fast as they can sweats a lot, in fact they sweat more water than they drink.
But people running for over four hours are not running at such a strenuous pace that they sweat more water than they take in. Thus endurance athletes are at risk of drinking too much water and diluting their sodium levels.
Doctors caution runners not to drink more than a bottle of water an hour. They also recommend you mix drinking water with drinks such as Gatorade, which include sodium. Also, only drink when you are thirsty.
Those helping out with the Charlottesville Marathon Saturday, April 16, have it covered.
"We have a water station every two miles," said Kronk. "We have Gatorade or water, so they can pick whatever one they want."