Two sides of the coin will be presented today.
The physiological side of the coin
Alessandro Mezzani
The intensity of aerobic exercise training is a key issue in cardiac rehabilitation, being directly linked to both the amount of exercise capacity improvement and the risk of adverse events during exercise.
Recent advances in the understanding of the physiological response to constant work rate exercise have made different exercise intensity domains identifiable with showing different cardio-respiratory response patterns. This information allows us to correct the bias introduced in the constant work rate exercise intensity prescription process by the use of data obtained with a different exercise model, i.e. incremental exercise testing.
Moreover, recent studies show that exercise intensity may be an important parameter for cardiovascular improvements. In this regard, special attention is now dedicated to aerobic interval training, i.e. a training modality which seems to provide superior effects on exercise capacity and left ventricular function with respect to more traditional forms of exercise.
The clinical side of the coin
Bonnie Sanderson
Regular exercise training is proven beneficial in improving physiological and psychosocial 
functions among individuals, including those with cardiac disease. Exercise training is a core component of cardiac rehabilitation and requires an individualised exercise prescription that maximises benefit, yet minimises risk.
Developing effective exercise prescriptions requires an understanding of the dose-response relationships of frequency, duration, and intensity of exercise; the exact composition will vary depending on the characteristics and goals of the individual. Exercise intensity remains one of the more challenging aspects in developing effective exercise prescriptions.
Standards for assessment and prescription of ET in cardiac rehabilitation, 16:30 - 18:00, Room 3, 15 April 2011