When it comes to exercise, can there be too much of a good thing? In this episode we take a deep dive into heart arrhythmias in endurance athletes, and the details of how and why long-term endurance exercise could cause a variety of heart arrhythmias. We’ll analyze the research, discuss warning signs, and give you an idea of how hard your heart is working when you’re doing that set of intervals or running a marathon. And, of course, we’ll discuss at length the evidence that suggests there could be too much of a good thing when it comes to exercise.