Long-term findings from a dyadic planning intervention with couples motivated to increase physical activity


  • N. Knoll
  • J. Keller
  • D.H. Hohl
  • G. Hosoya
  • U. Scholz
  • S. Burkert


Background: Individual action planning was shown to help increase physical activity. Dyadic planning involves a source of support in the planning process and refers to a target person creating plans together with a partner for when, where, and how the target person will act. We report 1-year follow-up findings of an RCT with couples investigating effects of a dyadic-planning intervention on physical activity and -fitness in target persons and partners. Relationship quality was explored as a moderator. Methods: Couples (N=338, target persons randomised) were randomly assigned to one of 3 conditions: a) dyadic-planning (DPC), b) individual-planning, where target persons planned and partners worked on a distractor task (IPC), and c) a no-planning dyadic-control condition (CC). Physical activity was objectively measured in 4 one-week assessments up to 1-year post-intervention. Cardio-respiratory fitness and relationship quality were assessed at baseline and 1-year follow-up. Multi-level models were fit. Findings: Compared to IPC- and CC-target persons, whose moderate activity increased up to 1-year post-intervention, DPC-target persons remained stable. Follow-up analyses indicated that only within the DPC, target persons with higher, as opposed to lower, a-priori relationship quality increased moderate activity (p<.10). DPC-partners showed steeper increases in cardio-respiratory fitness when compared to partners of the IPC, but not the CC. Discussion: A dyadic planning intervention appeared to have more beneficial long-term effects on planning partners than on target persons. Although a-priori relationship quality further qualified this pattern, findings resemble social support evidence indicating more beneficial effects for support providers than for recipients.