Posted: 01/02/2016 at 13:16
here's a sensible take on it:
Dermot Phelan, MD,PhD, Director, Sports Cardiology Center at Cleveland Clinic, did not participate in the analysis, but reviewed it and states that care should be taken in interpreting these results.
???Exercise and even strenuous exercise is clearly associated with enormous heart health benefits in the vast majority of people when compared to people who do not exercise but, in a very small minority who have underlying problems, exercise can trigger arrhythmia,??? he says. ???While there is emerging evidence that prolonged strenuous exercise can increase risk of atrial fibrillation, the long-term risk of this is small compared to inactivity.???
ie unless you are unlucky/already predisposed to having a dicky ticker your cardio will do far more good than harm. I'm not losing any sleep over this.