This randomized controlled trial compares supervised hospital-based practice with matched online activities as part of a common cardiac rehabilitation curriculum for cardiology residents. Ninety-eight residents will be allocated 1:1 to a blended group or an online control group. Both groups will receive the same seven-module online curriculum and the same total scheduled learning time. The blended group will complete a matched block of in-person practice in the cardiology ward, outpatient clinic, and cardiopulmonary exercise testing laboratory, whereas the control group will complete matched-duration supplementary online activities. The primary outcome is the post-training 25-item cardiac rehabilitation knowledge score adjusted for the baseline score. Key secondary outcomes are Mini-CEX and procedure-specific DOPS scores assessed by assessors blinded to allocation.