A runner's responsibility

• Check with your physician before registering for a marathon.
• Follow your training program.
• Determine what you need to stay properly hydrated.
• Dress for the weather.
• Don't run if you're not feeling well on race day.
• Change into warm dry clothing as soon as possible after the race.
• Fill out the medical information on the back of your race bib.
• Have an exit strategy: if you feel disoriented, seek medical attention.

Every year, around half a million people take part in marathons in North America. The vast majority of them cross the finish line in good medical condition. Yes, there is the odd death. In Toronto, four runners have died in marathons this decade.

You won't see many traumatic injuries during a marathon. Broken bones are rare, as are snapped Achilles tendons or ripped hamstrings. You will see runners with splotches of blood, where their sweat and the fabric in their shirts or shorts chafed their nipples or thighs enough to cause bleeding.

Most running injuries occur during the period leading up to a marathon, when a runner is in training.

"The most frequent cause of running injuries is over-training, or what could be termed the 'terrible too's,' " Dr Stephen Pribut, a sports podiatrist, says on his website. "Too much, too soon, too often, too fast, and too little attention paid to pain, all too often lead to injury."

By the time runners get to a marathon, they are usually well prepared. If not, there's normally a crack medical team in place to deal with those who are ill-prepared, or those who fall prey to the weather — the most common cause for health problems on race day.

Chris Troyanos has been watching the weather closely for the last 29 runnings of the Boston Marathon. He's the medical services co-ordinator for the annual race.

"Everything is dependent on weather. If you give me a temperature, I can almost give you a percentage of what injuries or casualties we will have that day."

If the race day temperature is around 7 C, Troyanos says his team of 1,300 volunteers will be busy dealing with cases of hypothermia — but not until after runners cross the finish line. Their body temperatures may be fine while they're running, but once they stop, their bodies begin to use energy to keep the core warm, leaving extremities cold.

Go to the other extreme — hot weather — and the problems can be more serious.

Heat attack

"We always talk about being prepared for the big one," Troyanos told CBCNews.ca. "And we always thought that we would be prepared, especially when we got that really rogue hot day. In 2004, we got that hot day, and we knew it was coming. We didn't understand the magnitude of what that kind of heat caused in an event of that size."

Twenty thousand runners spent a couple of hours waiting for the start in Hopkinton, Mass., as the temperature soared to 30 C — unseasonably hot for the middle of April. Troyanos says it wasn't long after the starter's pistol went off that he realized trouble was brewing.

"It was kind of like watching a train coming down the track, and you couldn't get off the track. You could hear it on the radios that people were dropping as early as Ashland, which is the second town in the race. Hospitals were going on diversion because they couldn't handle the flow and influx of runners coming in that were hurt, or injured or overheated. We weren't prepared for that, we couldn't respond, the hospitals weren't ready. For the guy who organized it, it was a bad day."

Troyanos decided to rethink the delivery of medical care for a large sporting event. He worked on improving co-ordination between the various local and state agencies involved and of developing strategies for quicker response to potential problems on the course.

"We started to develop a relationship with FEMA (Federal Emergency Measures Agency) and their DMAT (Disaster Medical Assistance Team) programs," Troyanos said. "They're the same type of programs that they would send out to a Katrina or something like that. We put three DMAT tents up with a full complement of doctors and nurses. It was like a little emergency room."

Canada's largest marathon is held in Ottawa in late May. The National Capital Race Weekend attracts more than 20,000 runners for all events. Medical co-ordinator Daniel Pilon says his staff of around 300 volunteers handles medical issues after the finish line. If you need help on the course, local Emergency Medical Service personnel will take care of you.

"Last year being quite hot, we expected to be treating a lot of runners for dehydration. But we didn't see many of them, because they were picked up en route."

Pilon says that if a runner is showing signs of difficulty, a volunteer will approach them to see if they want to drop out. If the person prefers to continue, a volunteer on a bicycle will monitor them to the next aid station.

Ottawa's volunteer team does not get any special training in dealing with the medical needs of marathon runners.

"All our volunteers are already medically trained," Pilon told CBCNews.ca. "They're either doctors, nurses, paramedics or have basic first aid.

Put to the test

Weather rarely causes medical problems at the Scotiabank Toronto Waterfront Marathon. Held in late September, the temperature is usually in the reasonable range for a marathon — somewhere between 12 and 18 C. But humidity can be a factor. If it's damp out, your sweat won't evaporate as quickly and your body won't cool itself as efficiently as it will on a drier day.

On Sept. 24, 2006, the weather was not a factor as seasoned runner Martin Poyser collapsed and died of a heart attack just short of the finish line. The 41-year-old man was running the half-marathon, a distance he had covered several times.

Emergency Medical Services personnel responded almost immediately but were unable to revive him.

Bruce Minnes is the medical director at the Waterfront Marathon and the associated director of the emergency room at Toronto's Hospital for Sick Children. He's also run six marathons. He says whenever there is an unexpected death — whether in the emergency room or on a race course — the medical team's response is always reviewed.

"We review everything — everyone's role, our response, the disease, everything," Minnes told CBCNews.ca. "When we reviewed Martin's death last year, we did the same. We spoke with the family and his running buddies regarding the care that was delivered. We didn't find anything lacking."

Aside from Poyser's death, the medical team treated about 50 people in 2006, a relatively quiet day considering there were more than 10,000 people taking part in all the races. Only a couple of people required intravenous treatment.

"You have to listen to your body," he said. "Typically those people who get into trouble are not listening to their bodies. If your goal is to have a life of running, sometimes you have to back off. Accept that you may have the odd bad race. Ignoring the warning signs can be fatal."

Developing standards of care

On Oct. 11, 2003, more than 40 medical professionals gathered at the headquarters of the Chicago Marathon, where they formed the American Road Race Medical Society. The group's goal is to help set standards for medical care at road races. The group sponsors conferences where race directors and medical co-ordinators can get together and compare medical strategies.

Troyanos says medical care at marathons is becoming much more organized and co-ordinated. And standards of care are emerging that event organizers can refer to.

Boston's medical team has made a point of getting a lot of information out to people taking part in the marathon about the importance of preparing for the weather and proper hydration.

In 2002, Cynthia Lucero collapsed four miles from the finish line. She was the second person to die in the history of the Boston Marathon. It wasn't her heart that gave out — it was a condition called hyponatremia, which is brought on by taking in too much fluid, which depletes essential minerals from the body. Women tend to be more susceptible to the condition than men — especially those who are on their feet for more than four hours.

Troyanos's team has always been aggressive in using intravenous fluids to rehydrate dehydrated runners. But giving fluids to somebody with signs of hyponatremia could be dangerous.

"Our protocol is that if you are going to get an IV, we know exactly what your sodium level is. So we're doing blood draws on every runner in one of our tents to determine their sodium. If you have a low sodium, you're not getting fluids, either IV or sometimes even orally until we know it's safe to do so." Troyanos says a lot of people don't realize how tough it is to run a marathon — even for well-trained athletes.

"In the New York marathon last year, Lance Armstrong did a lot for the sport with some of his comments," Troyanos said. "He said running the marathon was the hardest thing he's ever done. I'm applauding that — thank God, because people can now start to see that this isn't easy. This is one of the best-trained athletes in the world, and look how much he struggled to do a marathon."

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