Does endurance sport harm your heart?
Exercise is good for you in all kinds of ways, there is no medicine like it to prevent a whole range of illnesses. But for some endurance athletes, exercise also comes with increased risk of a heart condition called atrial fibrillation.
We look for the right way to think about the risks around exercise.
Reporter: Paul Connolly\nSeries Producer: Tom Colls\nSound Engineer: Graham Puddifoot\nEditor: Richard Vadon
(Picture: A cyclist training in the mountains\nCredit: anton5146/Getty Creative)