This work describes a motion-sensing enabled personalized exercise system for cardiac rehabilitation called CAROLS, capable of assisting healthcarers to find evidence-based effective exercise program for individual, and then motivating cardiac outpatients to improve their health recovery throughout a series of effective personalized rehabilitation exercises. In addition to making home-based cardiac rehabilitation exercise more effective and efficient, the CAROLS system can provide an interactive and user-friendly virtual gaming-environment for rehabilitation exercise in terms of monitoring real-time vital signs, increasing outpatient compliance for doctor prescription, as well as evaluating exercise efficiency and patient safety via a fusion function between a motion sensing technology and a wearable sensor device. The experimental system is in service trials with preliminary verification results including heart rate variability (HRV) analyses and motion similarity analysis of the 3-minute step test for normal users. Therefore, in addition to monitoring the exercise intensity and posture accuracy of outpatients, the CAROLS system provides clinical experts with a valuable reference for adjusting the exercise prescription in future scheduled return.