Abstract-Exercise training (ET) is one of the decisive and crucial factors for reducing and preventing unexpected cardiac events. The aim of this work is to implement a proactive eHealth system that will allow patients, following a Cardiac Rehabilitation (CR) program outside the hospital, to exercise safely, according to their recommended training zones. The eHealth system includes a smartwatch application, a smartphone application and several server-side applications, working on predefined personalised scenarios, which are alerting, guiding and supporting the patients. The heart rate (HR) of patients is continuously measured, recorded and analysed during ET with the help of wearable devices. While training, patients benefit from multiple levels of feedback. Communities of patients are created for stimulating and motivating patients to perform according to their CR program. Opposed to traditional home-based CR eHealth applications, profiles and training zones are created and handled dynamically for each patient.