Abstract : Cardiovascular disease (CVD) remains the world’s primary cause of premature mortality and economic burden. Exercise-based cardiac rehabilitation is a cornerstone for secondary prevention, however, the relative value of high-intensity interval training (HIIT) versus moderate-intensity continuous training (MICT) continues to be debated. This overview summarizes current physiological and clinical evidence to guide optimal exercise prescriptions in CVD. A comprehensive literature review of PubMed, Scopus, Web of Science and ScienceDirect databases was conducted utilising keywords and terms: Cardiac Rehabilitation, High-Intensity Interval Training, Moderate-Intensity Continuous Training, Coronary Artery Disease, Heart Failure and Telerehabilitation. After eligibility screening, 62 peer-reviewed articles- randomised trials, narrative reviews, meta-analyses and large cohort studies were included and narratively analysed with emphasis on physiological mechanisms, safety and clinical outcomes. Across multiple CVD populations, HIIT consistently produced larger short-term gains in peak oxygen uptake, greater improvements in endothelial function and autonomic balance, and comparable reductions in blood pressure and atherogenic lipids. MICT remained preferable for patients with low exercise tolerance or early post-myocardial-infarction. Adverse-event rates were low in both regimens. Hybrid and telerehabilitation programmes enhanced adherence without compromising safety or rehabilitation efficacy. Both HIIT and MICT are effective, safe strategies in modern cardiac rehabilitation. HIIT offers superior cardiorespiratory and vascular benefits within shorter sessions, whereas MICT provides a lower-strain alternative for high-risk or deconditioned patients. Personalised, stage-specific combinations, augmented by telerehabilitation techniques may maximise long-term participation and clinical outcomes.