Assessing levels of physical activity (PA) and providing feedback about these levels might have an effect on participant's PA behavior. This study discusses the effect of different levels of feedback--from minimal to use of a feedback display and coach--on PA over a 4-week intervention period. PA was measured at baseline, during and immediately after the intervention. Participants (n=227) were randomly assigned to a Minimal Intervention Group (MIG-no feedback), Pedometer Group (PG-feedback on steps taken), Display Group (DG-feedback on steps, minutes of moderate to vigorous physical activity and energy expenditure) or Coaching Group (CoachG-same as DG with need-supportive coaching). Two-way ANCOVA showed no significant Group×Time interaction effect for the different PA variables between the MIG and PG. Also no differences emerged between PG and DG. As hypothesized, CoachG had higher PA values throughout the intervention compared with DG. Self-monitoring using a pedometer resulted in more steps compared with a no-feedback condition at the start of the intervention. However, adding individualized coaching seems necessary to increase the PA level until the end of the intervention.
Keywords: exercise psychology; health promotion; motion sensors; physical activity assessment.