A blog by runners. For runners.

Study: another look at heart disease in marathoners – and their spouses

Is marathon running bad for your heart

We all know that running, and exercising in general, is good for us. Running strengthens our muscles, lungs, and hearts which reduces the risk of dangerous medical conditions, like heart disease (source).

But we’ve all also heard the sad stories of marathoners who died during the race – usually from an underlying heart condition. Every time this happens, the media, health professionals, and runners alike wonder “can too much running be bad for our health?”

Some studies show that intense physical exercise for long periods of time – such as marathon running – may be harmful for some people (source). Without getting thoroughly examined by a doctor, it’s nearly impossible to know if you’ll fall into this group.

Still, the risk of dying during or shortly after completing a marathon is extremely low – it only happens to 0.75 out of every 100,000 marathoners, according to Johns Hopkins research.

So the question remains: is distance running good or bad for your heart?

What new research says
A new study, published in the British Medical Journal, set out to determine if excessive exercise causes carotid artery disease (CAD). CAD is a type of heart disease that causes arteries to harden and fatty substances to build up within the arteries. Over time, this can block blood flow and cause a stroke – the third leading cause of death in the U.S.

The study compared 21 male and 21 female runners who finished the 2012 Boston Marathon. The runners averaged 40 miles per week during training, and finished the race in a mean time of 4:20 (keep in mind that it was dangerously hot during the 2012 race and most runners took 20-30 minutes longer to finish than normal.)

The marathoners’ spouses were used as the control group. The spouses weren’t runners, but they had similar diets and other lifestyle factors to the runners. This allowed the scientists to better isolate the effect of “excessive” running by keeping other variables pretty constant.

The researchers used a cIMT test to measure the carotid atherosclerosis of the runners and their spouses. The experts hypothesized that the marathoners would have less atherosclerosis than their spouses, but that wasn’t the case. There was no significant difference between the groups. However, both the marathoners and their spouses had about half the atherosclerosis of average people their age.

Not only does this study suggest that excessive running doesn’t cause CAD, but having a healthy lifestyle – just being married to a marathoner! – may lower your risk of the disease. Note that the runners had significantly lower body weights, body mass indexes (BMI), resting heart rates, and triglycerides, and a significantly higher high-density lipoprotein (HDL or “good”) cholesterol levels than their spouses. All of those factors have been shown to be protective against heart disease.

Of course, this is just one study that looked at one contributing factor to heart health. More studies need to be conducted before experts can say if endurance running is causes or protect against heart problems.

Written by Jen Matz.