I think the most relevant issue is to accomplish the recommendations of the most recent guideliness. It means to follow the General Principles for Exercise training in patients with heart diseases: Duration, Frecuency, Intensity, Type of Exercise and Individualization. Perhaps the most important item to avoid complications is the Intensity which it's possible to obtain through an Exercise Stress Test or calculate the training pulse or heart rate by a predicted formula: 220 beats per minute - years of age x 0.6 . Thanks.