This randomized controlled trial aims to compare the effects of High-Intensity Interval Training (HIIT) and Moderate-Intensity Continuous Training (MICT) in patients undergoing Phase II cardiac rehabilitation after coronary artery disease or post-angioplasty. A total of 66 participants will be randomly allocated into two groups: HIIT (n=33) and MICT (n=33). The intervention will be conducted 3 times per week using treadmill-based exercise protocols under heart rate monitoring. Primary outcomes include changes in left ventricular ejection fraction, functional capacity measured by 6-minute walk test, and lipid profile parameters before and after intervention. Secondary assessment includes health-related quality of life (HRQoL). The study aims to determine which exercise modality provides superior cardiovascular and functional improvement in stable cardiac patients during supervised rehabilitation.