Objective: To evaluate the effectiveness of a print-based intervention supported by Internet tools at improving physical activity in cancer survivors compared to a standard letter recommendation. Pre-diagnosis physical activity and self-efficacy were hypothesised to predict physical activity improvement.

Study design: Waiting list randomised control trial and cost-consequence analysis.

Methods: Adult cancer survivors who could become physically active without prior medical approval were randomised to receive either a print-based intervention supported by Internet tools (intervention, n=104) or a standard letter recommendation (control, n=103). Physical activity was assessed at 12-weeks with maintenance assessed at 24-weeks in the intervention arm. A number-needed-to-treat was calculated and a cost-consequence analysis completed.

Results: Participants in receipt of a print-based intervention supported by Internet tools improved their physical activity by 36.9% over 12-weeks compared to 9.1% in the control arm. Physical activity was maintained at 24-weeks in the intervention arm. Six-point-two-nine cancer survivors needed to receive the intervention for one to improve physical activity over a standard letter recommendation. Intervention delivery cost £8.19 per person. Pre-diagnosis physical activity and self-efficacy did not predict physical activity improvement.

Conclusion: A print-based intervention supported by Internet tools offers a promising low-cost means to intervene to improve physical activity in cancer survivors.