A feasibility randomized trial of an identity-based physical activity intervention among university students

INTRODUCTION: Exercise identity has considerable evidence as a correlate of physical activity (PA), but almost no research has focused on intervention. Theory suggests identity may be formed through indirect means of motivated behaviour change over time or through direct targeting of identity related antecedents. Using a parallel, single blind design, the purpose of this study was to explore the feasibility (recruitment, retention, and satisfaction) of these two types of interventions (indirect, direct) to increase exercise identity and subsequent PA. METHODS: Participants between the ages of 18–25 who were not meeting PA guidelines were recruited from the University of Victoria, and randomized at a 1:1 ratio to an indirect or direct intervention group. The indirect intervention group received information on the benefits of PA and behaviour change techniques such as planning. The direct intervention group received the same information, with the addition of identity-specific information. Intervention materials were delivered bi-weekly for 6 weeks. Feasibility and participant satisfaction at the study end-point were assessed using mixed methods, and both PA change and exercise identity change were assessed via self-report. RESULTS: Twenty participants were randomized to the direct or indirect intervention group (10 each), with 18 participants completing full study protocol. The recruitment rate was 26% and retention was 90%. Mean scores from the satisfaction survey (five-point scale) were high for both groups (indirect M = 2.69, SD = 0.62; direct M = 2.83, SD = 0.40). Both intervention groups increased their PA (η(2) = 0.25), and exercise identity levels (η(2) = 0.43) across six weeks. DISCUSSION: High feasibility ratings, both through retention, and survey and interview data show that the study could be extended to a full-scale RCT. Modifications to recruitment including oversampling to account for low recruitment rates may be useful. No adverse events were reported.