Earlier this week, a study was published that found that long-term distance running leads to heart complications and increased risk of heart attack. The paper was published in Missouri Medicine, the journal of the Missouri State Medical Association, whose cover was practically a gigantic warning sign against long-distance running:
Following the journal’s publication, various reputable news outlets reported the findings, with headlines such as ‘Walk away from excess running, researchers say’, ‘Science: Running Marathons Might Cause Heart Disease’ and ‘Too Much Running Tied to Shorter Life Span.’
James O’Keefe, preventive cardiologist at St. Luke’s Hospital in Kansas City, Mo. and co-author of the paper, said he advises runners to avoid strenuous exercise for more than an hour at a time and leaves runners with the following instruction:
“If you want to run a marathon, run one and cross it off your bucket list.”
No offense to James O’Keefe, but screw that.
Just kidding (kind of). I appreciate the scientific community conducting research on the health benefits and risks of endurance training, as such findings help inform behaviors of athletes and help us better understand health risks so that we may take any necessary preventive measures to maintain optimal health. That being said, there are caveats with this particular study that are too significant to be left unsaid.
In the study, scientists from the Minneapolis Heart Institute Foundation recruited fifty male participants who had run at least one marathon a year for 25 years and 23 male control subjects who reported leading a sedentary lifestyle. All of the participants were similar in age, resting blood pressure, height, smoking history and cholesterol levels. The researchers conducted coronary computed tomographic angiography (CCTA) scans on the participants in order to measure levels of calcified and non-calcified plaque in the heart—the latter of which is linked to increased heart attack risk.
The findings showed that the male marathon runners had more total coronary plaque volume—both calcified and non-calcified—than did the sedentary participants. The researchers concluded that running about 15 to 20 miles a week provides optimal health benefits, while exceeding that amount may paradoxically lead to accelerated coronary artery plaque formation. Researchers said that their findings refute the widely-held belief that “vigorous aerobic exercise is considered protective against coronary artery plaque development based on its favorable effects on many cardiovascular risk factors.”
Okay, here’s where you have to begin questioning the study’s validity. It is important to point out that this study was a single-center observational study, meaning that the study’s researchers observe subjects and draw inferences about the effect of an “exposure” or intervention on subjects. Compared to other types of research studies, observational research often lead to findings for which there are many potential alternative explanations. This issue is called “confounding” and is a primary challenge of observational research. What this means is that the researchers of the recent study cannot conclude that running itself caused the study’s results; there were many factors for which were left unaccounted.
At the end of the paper’s discussion, authors concluded with the following statement: “Ultra-endurance efforts also cause multiple other disturbances within the system including sustained elevations of catecholamines and resultant coronary vasoconstriction, protracted sinus tachycardia which reduces the diastolic filling time of the coronary arteries, changes in free fatty acid metabolism, lactic acidosis, and other metabolic derangements.” Oh no!! Sounds horrible, right? First of all, here’s what the hell that all means:
- “Sustained elevations of catecholamines and resultant coronary vasoconstriction”: Since the body is under physical stress when running, it releases catecholamines (hormones), such as dopamine, norepinephrine and epinephrine (aka adrenalin).
- “Protracted sinus tachycardia which reduces the diastolic filling time of the coronary arteries”: In English, this means that the heart rhythm becomes elevated to above the normal heart rate, which reduces the amount of time for the heart to refill with blood between muscle contractions.
- “Changes in free fatty acid metabolism, lactic acidosis, and other metabolic derangements”: Running affects the rate at which fatty acids are broken down and turned into fuel, builds up lactate levels and changes other metabolic processes.
Oh, so running gives you adrenalin, increases heart rate and makes our legs hurt??
I think it’s safe to say…no shit!
What the media outlets also haven’t been reporting is what the authors of the paper concluded on the last page:
“(Thus,) a cause-and-effect relationship between marathon running and accelerated coronary plaque development cannot be established.”
What I’m trying to say, in a nutshell, is that these hyped-up reports about the “dangers of running” are full of as much horse shit as were the trails I ran on this morning.
I’ve met plenty of people who have traded addictions—smoking, heavy drinking, bingeing on fast food and Netflix—for running, without which they would have been on a fast track to a prematurely dug grave. Based on my experiences, ultra runners are some of the most self-aware, insightful people out there who are truly excited about life’s limitless adventures—something sadly rare in today’s superficial, crooked world. They have a compassionate heart and a courageous spirit—manifested in their impact on the community and the difference they make when leading by example. They have an insatiable appetite for stretching the limits of both body and mind, and it is my belief that their memories of triumphing over once-seemingly-impossible endeavors, building unbreakable bonds with fellow life-lovers and simply spending a good chunk of their lives feeling the wind on their face, dirt between their toes and hard-earned sweat, are much more valuable than memories of vanilla, Comcast bills and a clingy relationship with a safety belt—regardless whether such memories are taken to the deathbed a few days early.
So is ultra running really bad for your heart? Sorry to all you Debbies out there, but I’d say it’s actually quite the opposite.
Happy running!
Sources:
http://www.philly.com/philly/health/Walk_away_from_excess_running_researchers_say.html
http://washington.cbslocal.com/2014/04/01/study-too-much-running-linked-to-shorter-lifespans/
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2920077/#!po=14.7059
trailsandkale.blog 
Thoughtful analysis. Thank you!