This study examines the effect of a video-based intensity level demonstration on self-reported physical activity in individuals aged between 40 and 75 years. Aim of the video demonstration is to achieve a better concordance of physical activity reports with accelerometer-based measurements.

This study examines whether the demonstration of different intensity levels of physical activity by video in the context of a tablet PC (personal computer)-based survey can achieve a higher degree of concordance between self-reported and accelerometer-measured physical activity compared to an assessment without video demonstration. The recruitment of the study participants in the age range between 40 and 75 years takes place in a shopping center in the city Greifswald in Germany.

Informed consent consists of: (i) activity recording over 7 days using an accelerometer, (ii) completion of standardized questionnaires, (iii) participation in a standardized measurement of weight and height as well as waist and hip circumference.

Participants are asked to wear an accelerometer during the day for a period of 7 days. Subsequently, a questionnaire about the frequency, duration and intensity of physical activity in the last 7 days will be answered in the DZHK (Deutsches Zentrum für Herz-Kreislauf-Forschung)- examination center. Prior to the physical activity assessment the study participants are randomly assigned to the study conditions "Video" or "No Video" (ratio 1:1). Optionally, participants may receive feedback on their physical activity measured by accelerometer upon completion of the study.

Inclusion Criteria:

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Exclusion Criteria:

• cognitive impairment
• inadequate language skills