Purpose <p>Most exercise interventions for men with prostate cancer utilise resistance and aerobic exercise, though the optimal combination of each for cardiometabolic health and quality of life outcomes is unclear. This study aimed to determine the feasibility of an aerobic-emphasised (AE) versus a resistance-emphasised (RE) exercise intervention in men with prostate cancer undergoing androgen deprivation therapy (ADT) and radiation therapy (RT).</p> Methods <p>A 6-month two-armed randomised feasibility study was undertaken. Prostate cancer patients (<i>n</i> = 24) undergoing ADT and RT were randomised to either an AE (<i>n</i> = 12) or RE (<i>n</i> = 12) supervised programme. The primary outcome was feasibility, assessed via recruitment, retention, adherence and safety.</p> Results <p>Twenty-four men were randomised, the recruitment rate was 19%. For AE and RE respectively, retention was 75% and 83%, adherence to the exercise prescription was 80% and 76%, attendance was 91% and 92%, with attendance during RT at 96% and 95%. No serious adverse events were recorded. Preliminary evidence favoured the AE intervention (<i>p</i> &lt; 0.05) for certain quality of life domains and haematology markers and the RE intervention (<i>p</i> = 0.05) for BESS balance scores. Pre- to post-intervention improvements (<i>p</i> &lt; 0.05) were observed in multiple functional fitness outcomes.</p> Conclusion <p>An exercise trial that carefully varies both resistance and aerobic elements is feasible for men with prostate cancer undergoing active treatment. Strategies would have to be implemented to increase recruitment for a larger trial.</p> Trial registration <p>The trial has been registered on ClinicalTrials.gov as of the 14^th of December 2021 (NCT05156424).</p>