Group walking sessions will be supervised twice weekly during the first four weeks of the programme to re-introduce exercise to participant's lives in a safe and structured manner. As the programme progresses the frequency of supervised sessions will decrease to increase participants independence with the protocol. In the absence of guidance on appropriate exercise prescription in cancer cohorts, exercise intensity will be prescribed in accordance with the American College of Sports Medicine (ACSM) guidelines for exercise in deconditioned populations (28). Initially, activity will be prescribed at a light intensity and will progress during the programme to a moderate aerobic intensity. The proposed starting intensity is based on pilot data from the investigators institute suggesting that aerobic fitness levels are either 'poor' or 'very poor' in the early post-treatment phase. Participants will wear Polar Heart Rate monitors during all sessions to ensure compliance with the exercise prescribed. The goal at programme completion will be participation in 30 minutes of moderate intensity activity five days per week, as per the ACSM physical activity guidelines.