Effects of Individual, Dyadic, and Collaborative Plans on Physical Activity in Partner-Partner Dyads

OBJECTIVE: The project aims at investigating of the effects of three types of planning (individual planning, collaborative planning, and dyadic planning) on physical activity among dyads.The influence of three planning interventions are compared with an active control condition, including physical activity education.

PARTICIPANTS: The effects of the interventions are evaluated among dyads of two adults (partner-partner dyads). Adults forming dyads (e.g. two romantic partners, two relatives, two co-workers, two friends) who are in regular contact for at least one year will be enrolled. A minimum of 50 dyads enrolled into the each arm of the trial (a total of 200 dyads). The interventions consist of six planning sessions.

DESIGN: The dyads are randomly assigned to one of four experimental conditions. The assessment of the main and secondary outcomes is conducted at the baseline, at 1 week after the first intervention session, at post-intervention (after six intervention sessions are completed), and at 6-, and 12-month follow-ups.

OUTCOMES: Physical activity constitutes the main outcome, whereas health-related quality of life (HRQOL), body mass index, and sedentary behavior as well as the self-regulatory strategy called the use of planning (individual, dyadic and collaborative) are secondary outcomes.

Individual planning (also known as implementation intentions or action and coping planning) is a regulatory strategy, which refers to making plans on when, where, and how to perform an intended behavior. In dyadic planning, a target person is setting plans together with a partner on when, where, and how the target person will individually engage in behavior change. The concept of dyadic planning differs from the conceptualization of collaborative plans, where two individuals make plans on how to enact a behavior together.

The study will evaluate the effects of a short-term planning intervention. The intervention includes a total of six sessions: two face-to-face sessions with the experimenter (delivered over two weeks) and three sessions delivered over phone (over the following three weeks), one face-two-face session (delivered at one month after the third session delivered over the phone). The delivery has an individual format (the experimenter + the dyad). The total time from first to sixth session is 2 months. The setting for the interventions will include physician's offices and participant's home. The same format, schedule, delivery, and setting will be used for conducting active control group procedures.

Eligibility Criteria:
Inclusion Criteria:

* Both partners in the dyad are adults
* At least one partner in the dyad does not meet the World Health Organization guidelines for physical activity for their respective age group and health status
* Participants are healthy or with a diagnosed chronic illness (without contraindications for moderate intensity physical activity
* The partners may be a romantic relationship or in another relationship: next of kin, family members, friends who are willing to join the study together
* The dyadic partners are in the stable relationship for at least one year or meet and spend time together regularly for at least one year

Exclusion Criteria:

* Any existing diseases with contraindications for moderate intensity physical activity, confirmed by patient's primary care physician or a specialist in cardiovascular diseases/endocrinology/rehabilitation medicine providing care for the patient during the recruitment and follow-ups
* Both participants in the dyad meet the World Health Organization guidelines for physical activity for their respective age group and health status in terms of minutes per week, the intensity of physical activity, and the types of exercises