Days in (light) motion: a dyadic planning intervention with couples to increase daily physical activity

Abstract

Background: Even with good intentions, being sufficiently physically active in daily life is often hard. Action planning was shown to help translate intentions into action by linking situational cues with planned behaviour. Extending individual planning to the level of the dyad, dyadic planning refers to a target person creating plans together with a partner for when, where, and how the target person will implement behaviour change. In this randomised controlled trial, we investigated if a dyadic planning intervention would increase daily physical activity in target persons and partners. Methods: Following a motivational treatment, 346 couples (target persons randomised) were randomly assigned to one of 3 intervention conditions: a) a dyadic planning intervention, b) an individual planning intervention where target persons planned and partners worked on a distractor task, and c) a dyadic no-planning control condition. Light, moderate, and vigorous activity were objectively measured in 3 one-week assessments up to 7 weeks post-intervention. Multi-level models were fit. Findings: Compared to target persons of the individual planning- (p<.10) and control conditions, only light activity increased in the dyadic planning condition. Overall decreases in moderate activity were less pronounced in the individual- (p<.10) than in the dyadic planning condition. Partners of the dyadic planning condition showed steeper initial increases in vigorous activity when compared to partners of the control- (p<.10) and individual planning conditions. Discussion: Brief intervention exposure, an active control group, and generally high a-priori levels of activity may have caused small effects that often did not meet conventional levels of significance.