With nothing better to do on vacation than rehab my knee (minor knee surgery), chase a 15 month old around a pool, and sip frozen drinks with umbrellas, my wife and I attempted to reduce our backlog of unread magazines. For me it was about four months worth of Men’s Health, Men’s Journal, Men’s Fitness, and Runner’s World magazines. What I found interesting was a number or articles related to the health risks and dangers associated with running a marathon. To save you from having to read the full articles, I thought I would share with you a brief summary.
Two of the more comprehensive, full length articles were featured in Men’s Health and Runner’s World. Both articles agreed that training for a marathon is very beneficial, but the actual event itself is such an undertaking that it moves the scale from being a benefit to a risk in some people depending on their pre-disposition and their training.
The MH article focused on a 2006 study on blood circulation of marathon participants. Using ultrasounds and blood tests, researchers found that some runners' hearts experienced difficulty refilling chambers and also noticed abnormalities in how blood was pumped from the right side of the heart to the lungs. This was due to increased inflammatory reactions and activity that occur all over the body during a long run like a marathon… the legs are not the only muscles that get sore after a long run.
“During the race and for several hours afterward, the systemic inflammation significantly increases your risk of a cardiac event, particularly if you're middle-aged and have some silent coronary-artery disease. Two things happen: First, inflammatory mediators released during muscle injury may make the thin, fibrous plaque that lines your artery walls more likely to rupture; second, this inflammation can lead to an imbalance of coagulation factors, making blood more susceptible to clots. The result: a heart attack.”
But, before you put your running shoes back in the closet forever, there are a couple points of good news to temper their findings. One, the impact to the heart on those who trained by running an average of 45 miles / week were dramatically less than those who trained less. Second, the results showing poor blood flow in the heart immediately after the race were not permanent.
The Runner’s World article had a similar conclusion but from a different angle. While it’s study was a little more thorough, it was less technical. If an individual is under the age of 35 and suffers a heart attack during a race, it’s most likely due to a heart defect – irregular heartbeat, enlarged heart, scar tissue, etc. This was true of Ryan Shay who passed away during the Olympic trials in 2007. For the record, he died at mile 5.5, so he would have died had it been a 10K. Individuals over 35 who suffer a heart attack during a race most likely already have some coronary-artery disease. The marathon just triggers the attack. As explained by RW, our arteries are like hoses of water… when normal flow is going through them, it’s like a garden hose – not a lot of pressure, not a lot going on. However, when you exercise, your heart rate increases and the flow of blood through the arteries increases, the arteries are more like a fire hose that needs three firemen to hold it down. If a person has any deposits of cholesterol on the insides of the walls, these could become jarred loose and cause a blockage at the heart. The marathon is the trigger that takes advantage of pre-existing condition.
If you do have a heart attack during a race, you have a 50 – 60% chance of survival as most runners are reached by an EMT in 5 minutes. Whereas, if you have a heart attack while on a normal run, you only have a 15% chance of survival. And what are the odds of a heart attack happening during a race? Three different studies put it at 1 in 75,000 to 1 in 110,000. That carries the same risk as drowning or being caught in a fire.
At the end of the day, exercise is good, but carries a transient risk. As one person put it, “if you want to live till you are 100, go for a run, if you want to live for the next hour, get in bed… alone”.
The risk is increased when you undertake a prolonged strenuous activity like a marathon. But, if you are properly informed, know where you fall on the heart attack risk chart, and have trained properly, you should worry less about having a heart attack during a race than you worry about having an accident while driving a car. So, enjoy every run, be motivated for every race, and celebrate every accomplishment.