The impact of implementation intentions in changing complex health-related behaviors in order to prevent weight gain: The case of physical activity.

Although intentions are regarded as the main determinant of behavior, positive intentions are often not translated in healthy behaviors, such as eating a low-fat diet or being physically active. Forming implementation intentions (II), i.e., a specific action plan as to when, where and how to act, show very promising results in overcoming this intention-behavior gap. However, these II are mainly studied in relation to relatively simply and straightforward behaviors. This project aims to test the possibilities of implementation intentions (II) as a tool for turning motivation into action for physical activity in a randomised controlled trail. Adult participants were recruited via worksites and newspapers, who were randomly allocated to one of four experimental conditions (control group, single II for physical activity, repeated II for physical activity, single II for walking). At the end of the pretest questionnaire, respondents were asked to increase their physical activity with at least two hours a week. The participants in the II groups were asked to write down:

1. what activity they were planning to do;

2. what day(s) they were planning to do this activity;

3. when they were planning the activity (e.g. before or after work);

4. where they would do the selected activity (e.g. in the park);

5. what time they would spent doing the activity.

This exact procedure was employed at three moments for participants in the repeated II condition and at pretest with respect to walking instead of self-selected activities for the single II for walking group. Post-tests took place at two weeks, three and six months post-intervention.

We hypothesized that forming implementation intentions may increase levels of physical activity.

N/A

Participants were randomly assigned to one of four conditions:

1. Control group;

2. Forming single implementation intentions for walking;

3. Forming implementation intentions for self-selected activities;

4. Forming repeated implementation intentions for self-selected activities.




At the end of the pretest questionnaire, all participants were asked to increase their physical activity with at least two hours per week.

The participants in the II groups (group 2,3 and 4) were additionally asked to write down:

1. what activity they were planning to do;

2. what day(s) they were planning to do this activity;

3. when they were planning the activity (e.g. before or after work);

4. where they would do the selected activity (e.g. in the park);

5. what time they would spent doing the activity.

This exact procedure was employed at three moments for participants in the repeated II condition (goup 4) and at pretest with respect to walking instead of self-selected activities for the single II for walking group (group 2). Forming implementation intentions took about ten minutes.