This is a news article based on an upcoming presentation at a scientific conference. This link does not report the appropriate control - age and gender matched (maybe BMI matched) individuals that do not participate in endurance sports. 18% of the male triathletes were reported to have ventricular fibrosis as interpreted from differential retention of a gadolinium compound that produces contrast in magnetic resonance images. But there is no report of the ventricular fibrosis in non-triathletes. I'll wait until this is published after peer-review by experts.