Background: Adolescents (11-18-year-olds) are at risk of physical inactivity. There is limited knowledge of physical activity (PA) levels among adolescents in the school setting in Hong Kong. We developed and tested a novel theoretical model of how household/family characteristics, school-level social and physical environmental factors and individual adolescent's characteristics impact on their school-based PA during and after school hours.; Methods: Cross-sectional study participants were Hong Kong adolescents attending secondary school, paired with their parent/caregiver (n = 1299 dyads). Parents survey-reported on household/family characteristics, parental PA and rules related to PA. Adolescents survey-reported on school PA-friendly policy, PA equipment at school (combined to create PA-friendly index), social support for PA from peers, athletic ability, attitude to and enjoyment of PA. Adolescents self-reported their school-based PA during school hours (physical education; recess) and after school (sports teams/classes). Objectively-measured moderate-to-vigorous PA (MVPA) was measured using accelerometers for a sub-sample of adolescents (n = 588). Generalized additive mixed models were used to estimate how household/family-level and school-level factors, and adolescents' individual characteristics were related to adolescents' school-based PA in Hong Kong, and to identify potential mediators of these associations.; Results: A complex network of potential pathways of influence on adolescents' school-based PA was identified. Overall, most of the significant effects were indirect ones. However, there were far fewer significant pathways between household/family characteristics and objectively-measured MVPA at school than there were for self-reported PA at school. In fact, there were no indirect pathways between these variables and MVPA at school. Gender disparities among pathways were identified. For example, school PA-friendly index was significantly associated with MVPA

The Active Healthy Kids 2019 Hong Kong Report Card on Physical Activity for Children and Youth with Special Educational Needs (SEN) provides evidence-based assessments for nine indicators of physical activity behaviors and related sources of influence for 6- to 17-year-olds with SEN in Hong Kong. This is the first Report Card for this population group in Hong Kong. The best available data between 2008 and 2019 were reviewed by a panel of experts. Following the Active Healthy Kids Global Alliance (AHKGA) development process, letter grades were assigned to nine indicators (Overall Physical Activity, Organized Sport Participation, Active Play, Active Transportation, Sedentary Behaviors, Family & Peers, School, Community & Environment, and Government Strategies & Investments). Two behavior indicators (Overall Physical Activity: F; Sedentary Behaviors: D+) and two contextual indicators (School: B; Government Strategies & Investments: C-) were assigned a letter grade. The remaining indicators including Organized Sport Participation, Active Play, Active Transportation, Family & Peers, and Community & Environment were not graded due to insufficient data. A majority of children and youth with SEN in Hong Kong are physically inactive and have a high level of sedentary behaviors. Schools are ideal settings to promote physical activity for this population. There is a need to develop a comprehensive surveillance system to monitor this population, assess efforts to improve the grades, and promote physical activity opportunities for children and youth with SEN. Copyright ©Elsevier (Singapore) Pte Ltd.