Exercise-based cardiac rehabilitation (EBCR) is paramount after an acute myocardial infarction (AMI). Older individuals have been reported as having a worse prognosis after an AMI, and some series have reported differences in the functional response to EBCR. The peak circulatory power (CP), a non-invasive parameter, has been described as a surrogate for the cardiac power, showing promising results as a comprehensive measure of the cardiovascular response. Whilst this, data concerning the impact of EBCR on CP, particularly among elderly individuals, remains elusive. To address this issue, an observational, retrospective study including all patients admitted due to an AMI who completed a phase II EBCR programme between 11/2012 and 4/2017, was conducted, with CP being analysed by a symptom-limited cardiopulmonary exercise test. A total of 379 patients, 30% aged \ge65 years-old, were included. CP significantly improved after the EBCR programme (in all patients, as well as in both subgroups). Older patients presented lower CP than their younger counterparts at the beginning and the end of the programme, while presenting smaller improvements (122 \pm 540 vs 293 \pm 638 mmHg mL/kg/min, p = 0.013). This was maintained after adjusting for several potential confounding factors. A contemporary ECBR programme was associated with significant improvements in CP among AMI patients. Though those aged \ge65 years-old presented smaller improvements in CP than younger individuals, these still presented significant increases in this parameter. These results highlight the importance of EBCR in this challenging higher risk group of patients.