Insufficient physical exercise contributes to many disease processes and increases mortality and morbidity rates worldwide. If the world population were to adhere to recommended levels of physical activity, health outcomes would improve. To that end, clinical practices need to consider exercise interventions to improve patient self-efficacy to adhere to recommended physical activity guidelines. A family nurse practitioner led such an intervention in a primary care clinic in Anchorage, Alaska. It evaluated a prescriptive-exercise program using the Exercise is Medicine® (EIM) guidelines of the American College of Sports Medicine. This pilot targeted healthy adults between 18 and 64 years old who were not exercising at least 150 minutes per week. From 20 applicants, eight participants qualified and entered into a 12-week prescribed exercise program. Seven completed the intervention and the subsequent post self-efficacy survey and measurement collection. Measured outcomes were self-efficacy, blood pressure, body mass index and participant’s commitment to follow through with continued exercise. Significant findings from this exercise intervention included (1) increased self-efficacy from “sense of accomplishment”, (2) reduced systolic and diastolic blood pressure and (3) indications that participants would continue physical activity level per recommended guidelines. It is conclusive that implementation of a prescription-exercise guideline in clinical practice can improve the population’s self-efficacy to adhere to the recommended levels of physical activity, and lower blood pressure. Meeting adequate physical activity levels mitigates disease development, improves health outcomes and reduces health care system costs.