Cardiac Damage From Endurance Exercise


From MedPage Today, Dec 6, 2011:

Intense endurance exercise — such as running a marathon — may induce cardiac damage confined to the right ventricle, a small study showed.

Highly trained endurance athletes had reductions in right ventricular function immediately after a race, although it mostly returned to normal about a week later, according to André La Gerche, MBBS, PhD, of the University of Melbourne in Australia, and colleagues.

However, a handful of the athletes had signs of subclinical myocardial scarring on cardiac MRI, “suggesting that repetitive ultra-endurance exercise may lead to more extensive right ventricular change and possible myocardial fibrosis,” the researchers reported online in the European Heart Journal.

Action Points:
* This study of 40 endurance athletes found evidence of right ventricular effects after an endurance event that largely resolved by six to 11 days later.

* Also, no concomitant left ventricular effects were observed.

There were no changes in left ventricular function, which “provides further circumstantial evidence for the emerging concept that the right ventricle may be more susceptible to exercise-induced injury [than the left],” they wrote.

The study included 40 athletes (mean age 37) who were participating in a marathon, an endurance triathlon, an alpine cycling race, or an ultra triathlon. All trained for more than 10 hours a week and had finished in the top quarter of a recent endurance race. None had cardiac symptoms or risk factors.

The researchers evaluated the athletes two to three weeks before the race, immediately after the race, and six to 11 days after the race.

Compared with baseline, right ventricular volumes increased, and all measures of right ventricular function worsened immediately post race. Left ventricular function was unaffected.

Levels of two biomarkers of myocardial injury — cardiac troponin I and B-type natriuretic peptide — significantly increased following the race (P≤0.003 for both). The changes were associated with reductions in right ventricular ejection fraction (P≤0.002 for both), but were unrelated to left ventricular ejection fraction.

Lower right ventricular ejection fraction was significantly associated with longer race duration and increasing peak oxygen uptake (P≤0.011 for both).

By six to 11 days after the race, most measures of right ventricular function had returned to normal, with the exception of right ventricular strain rates, which remained lower.

In the 39 athletes who underwent cardiac MRI, five had delayed gadolinium enhancement confined to the interventricular septum, indicative of subclinical myocardial fibrosis. These athletes had been competing in endurance sports longer and had lower right ventricular ejection fractions compared with those with normal MRI findings.

Because the study was not powered to assess clinical outcomes, the significance of the MRI findings requires further study, according to the authors.

The study “begs the hypothetical question whether repetitive longstanding bouts of arduous exercise result in the development of an acquired form of arrhythmogenic right ventricular cardiomyopathy,” Sanjay Sharma, MD, and Abbas Zaidi, MBBS, of St. George’s University of London, wrote in an accompanying editorial.

“The results provide food for thought and the data should be embraced to galvanize more detailed and longitudinal assessment of large groups of endurance athletes,” they wrote. “The potential for such projects is enormous considering the colossal increase in participation rates in endurance events such as the marathon.”


The Happiness Project


We really enjoyed this book and wanted to share it with you. True, Gretchen Rubin, talks about us in her NY Times Bestselling Book, The Happiness Project, which we might add is now in paperback.

She makes a resolution to “Exercise Better” and reveals the importance of exercise as one of the stepping stones toward a happier life. Certainly that is no surprise to any of us here at Inform Fitness or to any of our clients, but she talks about how she has tried strength training and weight training in the past and was never able to stick with it. Then she discovered Inform Fitness and explains how the Power of 10 slow motion method changed her life.

We are thrilled to have another happy client and well, as you can imagine, ecstatic about her sharing it with the world in her book. If you would like more information about The Happiness Project or to buy Gretchen’s book, please visit their website.

Inform Fitness Featured In Marie Claire


We are really excited to share that The Power of 10 Workout was featured in the November 2011 Issue of Marie Claire @ Work.

The article mentions Inform Fitness as one the options for the busy executive who only has a short lunch period to fit in a worthwhile workout. We couldn’t agree more.

You can read the article in our press section or at Marie Claire where they have the full article online.