The interest in marathon running has exploded during the past few decades, with more than 20,000 runners expected to cross the finish line Sunday in the Detroit Free Press/Talmer Bank Marathon. But is it dangerous to participate in a 26.2 mile run?
In 1976 there were approximately 25,000 people in the U.S. participating in marathons, but in 2012 the number has jumped to more than half a million, according to Beaumont cardiologist Justin Trivax, who has put together a study to find out if running a marathon is too much of a good thing.
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The effects of running
In 2009, three runners collapsed and died of heart-related problems during the Detroit Free Press/Talmer Bank Marathon. Two of the runners were participating in the event's half marathon.
Trivax and his research team recruited 25 participants from the 2008 Free Press Marathon as volunteer research subjects in a study.
“We tested them before (the marathon) and immediately after, and then six months after they ran the marathon with the most comprehensive testing known to us as cardiologists,” Trivax explained.
Blood tests, electrocardiography monitoring and cardiac magnetic resonance imaging were all administered – and the results?
“There are some significant and dramatic abnormalities, not only in blood work but also the right heart chambers during exercise become remarkably weak and dilated,” he said. “Enormous amounts of strain on the heart can lay down scar tissue.”
Repeat scar tissue can lead to abnormal heart rhythms and can “presuppose that population to cardiac events during extreme exercise,” Trivax said.
However, in looking at the amount of runners as opposed the amount of cardiac incidents, there is not an overall increase.
“The risk of cardiac event during marathoning has not increased but marathon running has had an increased popularity,” he said. “The risk remains the same – one in 200,000. Now that we have so many more marathon runners there are more deaths.”
Everything in moderation
Trivax made a second discovery. “Exercise – even a moderate amount of exercise – both protects against heart disease but also provokes heart disease.”
A person who works out at a gym four to five times a week – their risk of having a cardiac event increases by 40 percent during that hour – according to Trivax. But there is a positive to that one hour as well.
“In the other 23 hours of the day when they are not exercising, their risk is markedly decreased compared to a person who does not exercise,” he said.
Trivax, an avid runner himself, doesn’t demonize marathon running but goes with the Ben Franklin method – “everything in moderation.”
“It’s important to remember, the overall benefits of exercise far outweigh the risks," Trivax said.
But don't participate in "weekend warrior" type events – where normally sedentary people get out and participate in a strenuous activity – the doctor warned.
"Their risk increases about 60 times of the person who is physically active," he said. "If you can get out and exercise one hour then your risk is diminished the other 23 hours. That's the key to all of this. There is clearly a point where you can have too much of one thing."
So everyone should exercise, but if you’ve had any health problems – especially any cardiac-related ones – get your doctor’s OK first.
“The bottom line is anyone interested in long distance running - especially those who are 50 and older – but no matter their age, should be carefully evaluated by a cardiologist before beginning an exercise program," Trivax said. “The doctor will ask about your family health history for underlying congenital and acquired forms of heart disease. Any history of fainting or cardiac arrest during or shortly after a run deserves a full evaluation for structural and coronary heart disease. Our study also showed that if a runner experiences palpitations it may signal the occurrence of atrial fibrillation.”
The 2012 Free Press/Talmer Bank Marathon
When: Sunday, Oct. 21
Start/finish line: West Fort Street at Second Avenue, Detroit
- 6:58 a.m.: Disabilities Division
- 7 a.m.: Marathon, International Half-Marathon Run/Walk and 5-Person Relay
- 7:25 a.m.: 5k Run/Walk
- 11 a.m.: U.S.-Only Half-Marathon