The Exercise is Medicine Canada (EIMC) initiative promotes physical activity counselling and exercise prescription within health care. The purpose of this study was to evaluate perceptions and practices around physical activity counselling and exercise prescription in health care professionals before and after EIMC training. Prior to and directly following EIMC workshops, 209 participants (physicians (n = 113); allied health professionals (AHPs) (n = 54), including primarily nurses (n = 36) and others; and exercise professionals (EPs) (n = 23), including kinesiologists (n = 16), physiotherapists (n = 5), and personal trainers (n = 2)) from 7 provinces completed self-reflection questionnaires. Compared with AHPs, physicians saw more patients (78% > 15 patients/day vs 93% < 15 patients/day; p < 0.001) and reported lower frequencies of exercise counselling during routine client encounters (48% vs 72% in most sessions; p < 0.001). EPs had higher confidence providing physical activity information (92 ± 11%) compared with both physicians (52 ± 25%; p < 0.001) and AHPs (56 ± 24%; p < 0.001). Physicians indicated that they experienced greater difficulty including physical activity and exercise counselling into sessions (2.74 ± 0.71, out of 5) compared with AHPs (2.17 ± 0.94; p = 0.001) and EPs (1.43 ± 0.66; p < 0.001). Physicians rated the most impactful barriers to exercise prescription as lack of patient interest (2.77 ± 0.85 out of 4), resources (2.65 ± 0.82 out of 4), and time (2.62 ± 0.71 out of 4). The majority of physicians (85%) provided a written prescription for exercise in <10% of appointments. Following the workshop, 87% of physician attendees proposed at least one change to practice; 47% intended on changing their practice by prescribing exercise routinely, and 33% planned on increasing physical activity and exercise counselling, measured through open-ended responses.