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 , 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.
“She was just like other people her age,” said her husband, Keith Cherry. “She had two kids and wanted something to motivate her to get back in shape and lose the extra pounds, something other than the previous four years of having kids and eating.”
Bellamy trained with the National AIDS group — Cherry is a health care consultant who was the executive director of an AIDS association in Delaware for many years — and she never missed a session. She wanted to complete the 2002 Marine Corps in 5:45:50, a little more than 13 minutes a mile. Bellamy made it to the halfway mark at Capitol Hill in 2:52:55 and the 18-mile point in 4:02:19, a bit slower than her goal. And she was concerned about making it to the 14th Street Bridge at Mile 23 before the cutoff time, when the bridge is closed to runners and reopened to traffic.
At Mile 19, Bellamy complained to her husband of a bad headache and blurry vision, both symptoms of hyponatremia. She ran another mile before she went off the course to her husband; 3-year-old daughter, Isabel; 9-month-old son, Walker; and her brother. There she collapsed.
An EMS bike team responded first, signaling for an ambulance as Bellamy slipped in and out of consciousness. According to the case report, the medical personnel originally believed she was suffering from a heat casualty, so they administered oxygen and an IV with normal saline.
Her blood pressure was 178/102, but her pulse of 62 bpm was alarming (because it was not elevated like the blood pressure), pointing to a neurological event. By the time the ambulance reached the hospital nearly two hours later — Cherry said the driver got lost — she was conscious enough only to state her name and follow simple instructions.
“Once you have a severe neurological, the time between the symptoms and brain death can be very short, within minutes,” said Verbalis, who consulted on the case along with Dr. Stephen Clement, the treating endocrinologist when Bellamy was admitted to Georgetown.
The labs came back with telling data. Her sodium was just 123 milliequivalents/liter; a healthy sodium range is 136 to 144, and 130 is considered the onset of hyponatremia. In Boston, Lucero was even lower at 113, and she had been drinking excessive amounts of Gatorade, which essentially is water and sugar.
Within an hour, the CT scan revealed that Bellamy’s brain tissue had swelled, and there was nowhere for the swelling to go but down the brain stem. She never regained brain function and was taken off life support two days later.
The key to combating hyponatremia is education. Had Bellamy known that overdrinking was a danger, perhaps her life could have been saved. To that end, the Boston Marathon, which learned from its experience with Lucero’s death last year, sent a special warning to all runners in the 2003 race.
“Drink to stay hydrated, don’t overdrink,” the Boston Athletic Association stressed to its 20,000-plus entrants in a brochure intended to prevent both dehydration and hyponatremia. Boston officials also placed scales at the Red Cross stations along the route for runners to weigh themselves if needed. One woman from Virginia who was interviewed in the medical tent at the finish line drank two cups of water at every stop and gained two pounds to 118.
Clement and Verbalis urge runners to follow the guidelines established by USATF. The doctors encourage runners to take the Self-Testing Program for Optimal Hydration on the organization’s Web site, usatf.org.
“I’ve been studying hydration issues for 20 years, and I couldn’t tell in the latter stages of my marathon whether I was overhydrated or underhydrated,” Verbalis said. “The one-hour test of how much fluid you lose is a good method to determine your own rate of sweat.”
Officials at the Marine Corps Marathon have included a page in the race guide on hydration issues.
“Talk about an additional 20,000 flyers, when you get a bag with all this stuff in it, it doesn’t jump out at you,” explained long-time Marine race director Rick Nealis. “We’re going to have flyers available at the information booths at packet pickup. We’ve been posting information to our Web site year round, what came out of USATF and the American Running Association. And we are talking to our charity groups, Leukemia Team in Training and National AIDS — they are definitely aware of it.”