Here’s a post from Runner’s World mentioning a new study that compared the carotid arteries of Boston Marathon runners to their non running spouses. No difference was noted. See Details below.

Do Boston Marathoners Risk Heart Problems?
New study looks at carotid atherosclerosis of Boston runners.
By Amby Burfoot
Published
February 20, 2014
A new study of Boston marathoners used an interesting design to isolate if the runners’ training and racing, rather than a generally healthy “lifestyle,” contributed to signs of heart disease. The researchers used this design because they wanted to determine if excessive exercise causes atherosclerosis, as has been proposed by cardiologist James O’Keefe, among others.

Many epidemiological studies have shown that exercise and high fitness lower the risk of developing heart disease. On the other hand, the excessive exercise hypothesis argues that this is true for modest exercisers, but not necessarily true for those who run more than 20 miles a week and frequently race long distances.

The new study looked at 42 Boston Marathoners who had been running for 12 years, on average, and trained about 40 miles a week. They finished the 2012 Boston Marathon in an average time of 4:20 on a scalding-hot day when many runners took 20 to 30 minutes longer than usual to finish the race.

The researchers chose 21 male runners from the 2012 Boston race, and 21 females. This was the experimental group. The control group was their spouses, 42 women and men who aren’t runners but share the same home and many of the same habits as their spouses. “By incorporating cohabiting partners who presumably follow somewhat similar lifestyle habits, we tried to minimize diet and lifestyle influences to better isolate the effect of high-intensity endurance running,” lead author Beth Taylor, Ph.D., told Newswire. Taylor serves as director of exercise physiology research at Hartford Hospital.

Taylor and her colleagues used a cIMT test to measure the carotid atherosclerosis of the marathoners and their spouses. Carotid IMT can be a strong predictor of future cardiovascular events such as stroke and heart attack, Taylor notes.

The researchers hypothesized that the 42 marathoners (average age: 46) would have less carotid atherosclerosis than their spouses. This turned out not to be the case. In fact, there was no difference between the two groups. Both had approximately half the atherosclerosis of average 46-year-olds.

“This should be reassuring to marathoners,” notes Taylor. “Our study suggests that while endurance running is not a ‘magic pill,’ neither is it a loaded gun. To optimally modulate their cardiovascular health, runners need to continue to focus on diet, stress reduction, other risk factors, and regular checkups.”

While marathoners and spouses had the same degree of carotid atherosclerosis, the runners had significantly lower body weight (149 vs 170), significantly lower resting heart rate (57 vs 69), significantly lower BMI (24 vs 27), significantly lower c-reactive protein (.6 vs 1.6), significantly higher HDL (68 vs 58), and significantly lower triglycerides (76 vs 103).

The paper was co-authored by a half dozen other doctors noted for their contributions to the Boston Marathon’s medical efforts, particularly the finish-line medical tent. They concluded: “These data suggest that exercise may reduce cardiovascular events by mechanisms independent of the atherosclerotic process.”