Abstract
Cardiac rehabilitation protocols applied during the in-hospital phase (phase I) are subjective and their results are contested when evaluated considering what should be the three basic principles of exercise prescription: specificity, overload and reversibility. In this review, we focus on the problems associated with the models of exercise prescription applied at this early stage in-hospital and adopted today, especially the lack of clinical studies demonstrating its effectiveness. Moreover, we present the concept of "periodization" as a useful tool in the search for better results.