A Tailored Feasibility Study to Increase Physical Activity and to Reduce Sedentary Time

The intervention is based on the Health Action Process Approach. The first letter provides information on knowledge regarding sedentary time and physical activity as well as intervenes on self-efficacy depending on the mindset of participants (non-intender, intender, actor). The second letter focuses on benefits and barriers of physical activity as well as the role of social support for physical activity. In case of actional stage, the third letter intervenes on self-efficacy again and suggests action and coping planning. Otherwise, the letter includes ipsative feedback according to the second letter.