Exercise has been established to be safe and result in improved physical function and quality of life for cancer patients. Our team and others have consistently demonstrated that exercise improves physical and mental health in men with prostate cancer during and following completion of therapeutic interventions. More specifically, resistance and aerobic exercise have been shown to enhance the musculoskeletal system, improve cardiorespiratory capacity, prevent functional decline, improve sexual health, body composition, endocrine and immune function as well as overall quality of life. A recent and very exciting discovery suggests that, in some cases, exercise may actually suppress tumour progression. However, all of the exercise clinical trials to date have included patients during or following surgery, radiation or hormone treatment. There are no established recommendations for improving active surveillance adherence, slowing disease progression, delaying time to active curative treatment, or reducing active surveillance-specific anxiety and distress. Our aim is to determine the feasibility and efficacy of implementing a program of exercise medicine specifically prescribed to ameliorate the primary physical and mental health problems faced by men on prostate cancer active surveillance and explore potential mechanisms underlying the influence of physical exercise on markers of disease progression.