This dissertation, "Thinking the Unthinkable: Physical Activity Behavioral Change and Propensity for Rehearsal in Chinese Children" by Chun-man, Ling, 凌振文, was obtained from The University of Hong Kong (Pokfulam, Hong Kong) and is being sold pursuant to Creative Commons: Attribution 3.0 Hong Kong License. The content of this dissertation has not been altered in any way. We have altered the formatting in order to facilitate the ease of printing and reading of the dissertation. All rights not granted by the above license are retained by the author. Abstract: The continued surge in childhood obesity rates globally has created much impetus for researchers to develop intervention strategies effective in changing physical activity behavior during childhood. Despite such interest there has been limited success, and very rarely have cross-cultural applicability of these initiatives been considered. This thesis begins with an examination of the applicability of a Western-modeled school-based intervention, America on the Move, using pedometers and point-of-choice prompts in an attempt to change the walking behavior of Chinese Hong Kong children (Chapter 2). To achieve this, the intervention mapping protocol was followed. The process comprised three studies. First, health messages prompting walking behaviors were developed and tested for motivational properties. Second, two piezoelectric pedometers were validated for our target population, and finally, a 7-week pilot of the intervention using the validated health messages and pedometers was implemented and evaluated among 8-12 year old Chinese Hong Kong children. The second part of the thesis took the unexpected results of the pilot intervention and explored how a goal-related psychological construct, emotional rehearsal, which has been associated with dysregulated health behaviors, may contribute to these. This part commences with an overview of the conceptualization of rehearsal and presentation of a conceptual model between stress and dysregulated health behavior mediated by the propensity for rehearsal (Chapter 3). Three studies were then undertaken to examine the relationship between rehearsal and dysregulated physical activity behavior. First, a Chinese version of the Rehearsal Scale for children (RSC-C) measuring propensity of rehearsal in children was adapted and validated for use in the subsequent two studies (Chapter 4). The second study investigated the existence of pedometer reactivity and how this might interact with propensity for rehearsal (Chapter 5). Lastly, the relationship between rehearsal and child health was examined through an assessment of the propensity for rehearsal and central adiposity status. Taken together, results of these empirical studies show promise in supporting the proposition that the effectiveness of intervention strategies may be culturally bound via the propensity for rehearsal and its link with cardiovascular health. Limitations of this thesis and future research directions are explored in the final chapter. DOI: 10.5353/th_b4784947 Subjects: Physical fitness for children - China - Hong Kong