Too much of a good thing

Drinking too much water during a marathon can kill you.

The deaths of a 35-year-old woman at last year’s Marine Corps Marathon and a 28-year-old woman at the Boston Marathon six months earlier were attributed to hyponatremia, the result of fluid intake exceeding fluid depletion.

The condition, formally known as hyponatremic encephalopathy, results in a critical imbalance between water and sodium levels. When the blood has too much water and too little sodium, brain cells absorb too much water, which causes the brain to swell and the tissue to push against the skull and sometimes down the brain stem. It can lead to nausea, fatigue, vomiting and, in the most severe instances, seizures, coma and even death.

“In the past, the recommendation was to overhydrate,” said Dr. Joe Verbalis, chief of endocrinology at Georgetown University Hospital. “Now it is to replace as much as you lose, a 1-to-1 replacement.”

Hyponatremia had been an issue with Ironman triathletes and other ultra-distance athletes for decades, but it was not until 1985 that researcher Timothy David Noakes of the University of South Africa at Cape Town published a report that termed hyponatremia a potentially dangerous and fatal issue for runners, especially novice women.

And with the increase in the number of people running for charity, novices have flooded marathon courses in the last eight years; 12,500 first-time marathoners will compete at Sunday’s Marine Corps. That means the average amount of time on the course has increased to as much as five, six or seven hours. Add to that the increase of the number of water stops on the courses these days — from one or two in the past to one every two miles now — and it’s no surprise that excess drinking has become a problem.

Though there have only been seven documented fatalities because of hyponatremia, several studies have shown high numbers of marathoners at the finish line suffering from some degree of the condition. In fact, one study that tracked 18,000 marathoners found that among those seeking medical care after the race, 9 percent suffered from it.

Some 21 of the 5,082 finishers at the 2000 Houston Marathon developed hyponatremia, with 14 requiring hospitalization.

Hilary Bellamy of Silver Spring never made it to the finish line of the Marine Corps Marathon last year. She collapsed in the arms of her husband around the 20-mile mark near West Potomac Park and later died, leaving two young children.

Bellamy seemed to do everything right in her first marathon. She trained hard for months with her organized training group and raised her required funds for the Whitman Walker Clinic-sponsored National AIDS Marathon Training Program. She followed the instructions on diet, rest and hydration. She always kept a bottle of water on her desk at work because she was made quite aware of the dangerous effects of dehydration over the course of 26-plus miles.

She died because she drank too much water while running with symptoms strikingly similar to those of Cynthia Lucero, who died after running 22 miles of the Boston Marathon six months earlier.

“No question that the best potential therapy would have been prevention, that she shouldn’t have overdrank,” said Verbalis, who tested his own fluid loss during his only marathon — a five-hour trek — in France some years ago. “No doubt she overdrank to her sodium levels. If she had followed the guidelines adopted by USA Track & Field in April [2003], she wouldn’t have had this problem. All these cases could have been prevented. The guidelines weren’t available at the time.”

The guidelines suggest that runners consume a liter of fluid for every liter lost during a race. Bellamy, following her training regimen, apparently drank as much as she could hold.

Bellamy was like many other area women, juggling family and career. She wrote policy research reports for Health Systems Resources Inc. in the District, focusing heavily on issues concerning the elderly and children and their lack of access to medical care.

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