Specificity of plans for physical activity: does a planning partner make a difference?

Abstract

Background: Planning to translate intentions into health behavior change has been shown to be an effective intervention strategy for individuals. In dyadic planning interventions, two partners jointly plan a target person’s health behavior change. The aim of this study was to compare plan specificity of an individual and dyadic planning intervention to enhance physical activity. We also tested associations between plan specificity and plan commitment as well as physical activity. Methods: Within two arms of an RCT with 346 heterosexual couples, randomly assigned target persons of an individual (n = 114) or dyadic planning intervention (n = 111) formulated up to 5 physical activity action plans which were rated regarding their plan specificity. Self-reported plan commitment and accelerometer-based moderate to vigorous physical activity (MVPA) were assessed 1 and 7 weeks post intervention. Findings: Most target persons formed 5 plans (individual planning group: 92.1%; dyadic planning group: 90.9 %). Individual plans (M = 2.41) and dyadic plans (M = 2.39; scale: 1 to 3) were both highly specific. Plan specificity of plans generated in the individual planning condition was not related to plan commitment, but negatively linked to MVPA 7 weeks post intervention. Regarding specificity of dyadic planning, we did not find a relationship with MVPA, but a positive association with plan commitment 1 week post intervention. Discussion: Plan specificity seems to be unrelated to the planning format (i.e., individual vs. dyadic). Future studies should address qualitative characteristics of the self-generated content of action plans as potential mechanisms of planning interventions.