Promoting Physical Activity in Overweight Couples: Effectiveness of a Dyadic Action Control Trial (DYACTIC)

Abstract

Background: Health behavior change models identify effective self-regulatory skills for behavioral change, but the social context is usually neglected. This study investigated the effectiveness of a dyadic conceptualization of action control for promoting physical activity. Methods: 121 overweight individuals and their partners were randomly allocated to one of two experimental (dyadic vs. individual action control) and two control conditions. Participants completed questionnaires at baseline (T1) and four weeks later (T2) including measures of action control and 7-day recall physical activity. Findings: Results showed that action control significantly increased from T1 to T2 and was overall higher in the experimental conditions compared to control conditions. In terms of physical activity, no overall intervention effect emerged. However, post hoc analyses revealed higher mean levels of sport activities in the dyadic intervention group compared to all other groups. Discussion: Overall, findings provide first support for the usefulness of a dyadic action control intervention, and suggest further investigation of objective measures of physical activity and secondary outcomes.