A 12-week Intervention With Motivational Interviewing and Physical Activity Monitoring, to Enhance the Daily Amount of Physical Activity in Community Dwelling Older Adults - a Randomized Controlled Trial

To investigate if motivational-interviewing will enhance the expected effect from physical activity monitors, on physical activity in older adults, we will conduct a two-arm randomized controlled trial in 2019. Both groups in the trial will receive a physical activity monitor for everyday use in the 12-week intervention period and a folder with information about the benefits of physical activity in older age. Participants in the intervention group will in addition to the use of the physical activity monitors receive a motivational feedback session by phone of about 20 minutes constructed from the theoretical framework of Motivational interviewing by Rollnick, Miller \& Butler and Social Cognitive Theory by Bandura. The content of the session focuses on investigating the most relevant possibilities and barriers for the participant to increase his or her levels of PA. The primary outcome will be between group difference in average steps per day throughout the intervention period, measured objectively by the physical activity monitor (Garmin Vivofit 3). Secondary outcomes include participant reported outcome measures such as 'International Physical Activity Questionnaire', 'Nordic Physical Activity Questionnaire', 'EQ5D Quality of life questionnaire', 'UCLA Loneliness Scale', 'Self Efficacy for Exercise', and 'Outcome expectancy for Exercise'. To ensure 80% power with an alpha-level on 0.05, we will include 128 participants. The study will enroll in March 2019.