Promoting participation in physical activity using framed messages: an application of prospect theory.

OBJECTIVES Messages designed to motivate participation in physical activity usually emphasize the benefits of physical activity (gain-framed) as well as the costs of inactivity (loss-framed). The framing implications of prospect theory suggest that the effectiveness of these messages could be enhanced by providing gain-framed information only. We compared the effectiveness of gain-, loss-, and mixed-framed messages for promoting moderate to vigorous physical activity. DESIGN Randomized trial. METHOD Sedentary, healthy callers to the US National Cancer Institute's Cancer Information Service (N=322) received gain-, loss-, or mixed-framed messages on three occasions (baseline, Week 1, and Week 5). Social cognitive variables and self-reported physical activity were assessed at baseline, Week 2, and Week 9. Separate regression analyses were conducted to examine message effects at each assessment point. RESULTS At Week 2, gain- and mixed-framed messages resulted in stronger intentions and greater self-efficacy than loss-framed messages. At Week 9, gain-framed messages resulted in greater physical activity participation than loss- or mixed-framed messages. Social cognitive variables at Week 2 did not mediate the Week 9 framing effects on physical activity participation. CONCLUSIONS Using gain-framed messages exclusively may be a means of increasing the efficacy of physical activity materials.