I was told recently by a cardiologist specializing in arrhythmia (electrophysiologist) that, indeed, exercise lowers the risk and sometimes eliminates arrhythmia BUT , of course, one must ascertain one does not have a dangerous arrhythmia or a heart that is not structurally normal and one is ok'd for beginning a new exercise routine. Exercise helps in many ways including lowering stress hormones that can spark arrhythmias and helping balance the automonic nervous system ( i.e. the parasympathetic and sympathetic nervous system which, when out of balance, can cause skipped beats).