Full story:
Running May Be Harmful to Your Heart
Running May Be Harmful to Your Heart
By Lisa Collier Cool
Nov 30, 2012
Running, long considered a healthy hobby, may actually be dangerous for some. At least that’s the prevailing opinion of a number of the country’s top cardiologists and a new study due out next month from British journal Heart...
According to James H. O’Keefe, M.D. of the Mid-America Heart Institute of Kansas City, who co-authored an extensive 2012 study that examined the cardiac risks faced by athletes: “Physical exercise, though not a drug, possesses many traits of a powerful pharmacologic agent. A safe upper dose limit potentially exists, beyond which the adverse effects of physical exercise, such as musculoskeletal trauma and cardiovascular stress, may outweigh its benefits.”
In short, exercise is great in small doses, but too much physical exertion too quickly or for too long a period can actually put a person’s heart at risk, especially if he or she is over age 35...
A quote from the study (linked in the box above):
"Emerging data suggest that chronic training for and competing in extreme endurance events such as marathons, ultramarathons, ironman distance triathlons, and very long distance bicycle races, can cause transient acute volume overload of the atria and right ventricle, with transient reductions in right ventricular ejection fraction and elevations of cardiac biomarkers, all of which return to normal within 1 week. Over months to years of repetitive injury, this process, in some individuals, may lead to patchy myocardial fibrosis, particularly in the atria, interventricular septum, and right ventricle, creating a substrate for atrial and ventricular arrhythmias. Additionally, long-term excessive sustained exercise may be associated with coronary artery calcification, diastolic dysfunction, and large-artery wall stiffening. However, this concept is still hypothetical and there is some inconsistency in the reported findings."
