Individually adapted physical exercise training under medical supervision is an important building block in the rehabilitation and secondary prevention for patients with cardiovascular diseases. Ambient assisted living technology permits such training to be carried out in the familiar home environment while at the same time reducing the risk of an adverse cardiovascular event. Against this background this article describes the requirements of a system for cardiac tele-rehabilitation at home and in particular discusses the components controlling a training session, which needs to recognize critical patient states through a continuous monitoring of vital signs and react accordingly. Furthermore, the health related data collected during such exercise training sessions provides useful information for patient care. Results need to be made available to the cardiologist responsible for follow-up e.g. in the form of structured training reports. The challenges involved in integrating data acquired at home with the professional healthcare IT infrastructure based on vendor-independent medical IT standards are also discussed.