Using financial incentives to increase physical activity, weight loss and well being: a randomized control trial

Objective: To compare the effects of implementation intention prompts and financial incentives, on promoting physical activity in individuals who are relatively inactive. A secondary objective was to determine the effect of physical activity on psychological well-being. Method: 98 participants were recruited, with a total of 66 participants (22 males, 44 females, mean age= 26.39 (SD= 5.00)) completing the intervention. Participants were randomly assigned to one of three groups; Financial Incentive (FI) group, Implementation Intention Prompt (IIP) group or a Control group. Weight, self-reported physical activity (International PhysicalActivity Questionnaire (IPAQ)) and psychological well-being (General Health Questionnaire-12 (GHQ-12)) were completed pre and post a six week intervention. Both the control group and FI group had no contact with researchers throughout the intervention period. The FI group received a discounted price (33% off) for a fitness and exercise program. The IIP group did not receive a discount, but received an initial group consultation, educating them on the use of implementation intention prompts, goal setting and two additional individual physical activity consultations, in which activity plans were reviewed and modified in line with physical activity health guidelines. All participants took part in a fitness and exercise program during the intervention. The program was administered by professional fitness trainers in Dublin, Ireland. A total of 10 classes were held each week, participants were encouraged to attend a minimum of 2 each week. Results: Self-reported physical activity increased across both intervention groups, when compared to the control group. There were significant increases in mean weight loss for the FI group (6.4kg, SD=1.4kg) and IIP group (6.3kg, SD=1kg) compared to the control group (1.6kg, SD=2.2kg). A small positive correlation (r=0.28) was found between increased physical activity and improved mental health. Conclusion: FI and IIP are equally effective methods of increasing physical activity levels and weight loss in previously inactive individuals. These findings have implications for health promoters and the fitness industry.