Inclusion Criteria:  >= 18 years of age Diagnosed with localized or asymptomatic metastatic primary prostate cancer Not currently undergoing radiation or chemotherapy Proficient in English Not physically active (self report <150 minutes of moderate-to-vigorous physical activity per week) Self-report >8 hours of daily sedentary behaviour In the contemplation or preparation stage for motivational readiness to change as determined by the Stages of Change Questionnaire Access to a smartphone, tablet, or computer No cardiac contraindications (e.g., unstable angina, arrhythmia, heart failure, aortic stenosis) Medical clearance from a primary health care provider (if necessary) Currently residing in Canada  Exclusion Criteria:  Not planning to live in Canada for the next 12 months A medical condition that prohibits walking (e.g., severe knee or hip arthritis) Presence of other primary or recurrent invasive cancer (i.e., other than non-melanoma skin cancer) Have had a prior fall within the last 12-months Use a gait aid device