Abstract Background and Purpose Cardiac rehabilitation program (CRP) is an interdisciplinary intervention aimed to improve exercise tolerance, promote the reintegration of patients with heart disease into their normal lives, and reduce the rate of long-term complications and mortality. Of the three phases, Phase II is responsible for achieving sufficient and safe gains to guarantee adaptation, but it is in Phase III where the long-term beneficial effects and self-management will be achieved. Nevertheless, only 30% - 60% of patients report continuing regular exercise during this stage, adherence rates are heterogeneous, and the diversity of results sustained over time is wide. Therefore, cardiac telerehabilitation (CTR) emerged as an affordable tool to achieve closer and safer surveillance at Phase III. The aim of the study is to evaluate the impact of CTR on exercise tolerance, safety and phase III adherence in patients with ischemic heart disease (IHD) Methods Quasi-experimental study that follows Phase II, in which patients with IHD were assigned to virtual sessions at 1st, 3rd, 6th and 12th months, In each session, they were questioned about adherence to training, exercise tolerance, symptoms, outcomes and control of cardiovascular risk factors (CVRF). The percentage of moderate in relation to vigorous physical activity was also evaluated. After one year they underwent a cardiopulmonary exercise test to analyze comparisons in cardiorespiratory fitness (CRFit) and control of CRF between the end of Phase II and the annual follow-up of Phase III. Results At one year of Phase III follow-up, a significant gain in VO2p and maintenance of the other variables associated with fitness such as oxygen pulse (OP2) and VE/VCO2 slope were evident, with a reduction in weight and diastolic blood pressure. There was a significant gain in CRF measured by VO2p and METs-load in those patients who maintained adherence to CTR Phase III (p=0.0001, see figure), with more improvement in those with attendance>50% (2 or more virtual sessions; p=0.008 and p=0.004 , respectively). A directly proportional correlation was observed between the percentage of attendance and the percentage of vigorous physical activity (p<0.01, Pearson r=0.46, CI 0.16-0.68). A positive and significant correlation was observed between the percentage of attendance at CTR Phase III and the number of METs-load (p<0.05, Pearson r=0.36, CI 0.05-0.61), as well as positive and significant correlation with the amount of VO2p (p<0.01, Pearson r=0.50, CI 0.21-0.70) at the end of Phase III. No cardiovascular adverse events were reported. Conclusion CTR strategy in Phase III is safe, effective and has high adherence rates among patients in our population, achieving control of CVRF, maintaining levels of METs-load and obtaining even greater increases in VO2p at one year of follow-up compared to those obtained at the end of Phase II.