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Endurance sports such as cycling, running and triathlon have surged in popularity in the past 10-15 years.  Marathons, IronMan triathlons, and ultra running events are picking up more and more participants.  As a healthcare provider, I see many of these endurance athletes in my clinic for sports related musculoskeletal injuries, and most of my own athletic pursuits over the last 15 years have centered around endurance sports such as cycling, triathlon and running.  Over the years of working with these athletes, I became well-versed in the typical injuries that happen to these types of athletes.  What I did not think about, however, was the adaptations that occur in the cardiovascular system including the heart, lungs, arteries and veins.  I just assumed that “it was all good” for the cardiovascular system.  After all, regular exercise is supposed to be protective against cardiovascular disease, diabetes, high blood pressure, etc.

Personally, I’ve been an endurance athlete my entire adult life.  I started racing mountain bikes in my early 20s and then added road racing, criteriums and time trials as I found that I had a bit of natural ability going for me.  I read books about training, bought a heart rate monitor, and was one of the beta testers for the original Power Tap bicycle power meter.  I eventually started competing in triathlons, and raced up through the 1/2 IronMan distance.  I also picked up Track racing and Cyclo-Cross after moving to Portland, started a racing team, and had a great time with racing.

Over the last several years, with evolving work and family responsibilities, I’ve had to step back from my commitment to racing.  I set different goals for myself health and fitness-wise, and one of the big health goals for me was to try and undo some of the musculoskeletal problems that had resulted from so many years of endurance training, leaving me with aches and pains that would not go away with rest.  Some of these were typical postural problems from cycling, some were overuse type injuries, and some were from injuries suffered from crashes including 3 collar bone fractures, broken ribs 5 times, and hitting the deck at race speed countless times.

Along with this, I’ve started to hear about more and more research that suggests that “going big” with endurance sports might not be good for you.  In fact, it might be downright harmful.  I know as a healthcare provider that endurance sports can cause musculoskeletal injuries, and most endurance sports participants are familiar with the fact that most participants end up with mild aches and pains associated with training and racing.  Most of these musculoskeletal problems are not a big deal.

However, new research is suggesting that your heart and arteries might suffer permanent scarring and damage from endurance training and competition.  Here are three summaries that I came across today:


Runners May Live Longer, But Extreme Endurance Exercise May Damage Heart.
The CNN (6/5, Kounang) “The Chart” blog reports, “The old adage, “all good things in moderation,” may be true, especially when it comes to exercise,” according to two new studies.

HealthDay (6/5, Marcus) reports, “Runners appear to live longer, new research suggests.” However, “there is likely a tipping point, concluded the authors of another new study that looked at the cardiovascular health of endurance athletes, when the heart no longer benefits and may even suffer damage.” In the first study, presented at the American College of Sports Medicine meeting, researchers “used data from the National Death Index and found that the runners had about a 20 percent lower mortality rate than the non-runners, said lead researcher Dr. Chip Lavie.”

The UK’s Telegraph (6/5) reports that the other study, which was “a review of research on endurance exercise conducted by a team at the respected Mayo Clinic in Rochester, America, found extreme endurance exercise such as marathons, iron man distance triathlons, and very long distance bicycle races may cause structural changes to the heart and large arteries.” The research, “published in the journal Mayo Clinic Proceedings…found that some athletes suffer temporary changes in their heart function which return to normal in the week after their race, however for others permanent scarring occurs.”

The Time (6/5, Rochman) “Healthland” blog reports, “Among 14,000 runners, the optimal amount of exercise appeared to be about 10 to 15 miles per week.” One of the researchers said, “We were thinking that we would see progressively more benefit the more you ran,” although “we thought it would level off at some point. But not only did the runners not get more benefit, but the more they did, the faster they ran, the more frequently they ran, the more miles they ran, they actually seemed to lose any benefit to the heart.


As a healthcare provider and endurance athlete, these things are important to me.  As an aging endurance athlete, I’ve had enough time to experience first-hand some of the negatives of endurance training, and this bit of information about potential damage to the heart and arteries is something that will keep in mind as I am planning my fitness goals.  I will certainly be mentioning it to the athletes that I work with.

Should you do anything different with your racing and training?  It depends.  Everybody has to make their own choices.  My goal is to simply provide a bit more information to guide your decision.