Delivered by Ingenta to: Ryerson University Library IP: 37.18.42.112 on: Sun, 05 Jun 2016 11:54:01 Copyright (c) PNG Publications. All rights reserved. 674 Neighborhood Environment, Self-efficacy, and Physical Activity in Urban Adolescents Carolyn C. Voorhees, PhD; Alice F. Yan, MD, PhD; Kelly J. Clifton, PhD; Min Qi Wang, PhD, FAAHB Carolyn C. Voorhees, Research Associate Pro- fessor and Min Qi Wang, Professor both from the Department of Behavioral and Community Health University of Maryland School of Public Health, College Park, MD. Alice F. Yan, Assistant Profes- sor, University of Texas at San Antonio, Depart- ment of Health and Kinesiology, San Antonio, TX. Kelly J. Clifton, Associate Professor, Port- land State University, Portland, OR. Email correspondence to Dr Voorhees, ccv@umd.edu Objectives: To test the path- ways between perceptions of built environment factors and physical activity in urban youth. Methods: Three hundred fifty high school students’ perceptions of neigh- borhood, and barrier self efficacy were measured by a Web survey. Physical activities were assessed using a one-week diary and accel- erometers. Results: Land-use mix/ accessibility and neighborhood satisfaction had direct pathways to walking. Barrier self-efficacy had a direct pathway to walking. In addition, land use, specifically neighborhood accessibility, influ- enced adolescents’ walking be- havior via self-efficacy. Similar pathways were found in MVPA models. Conclusions: Neighbor- hood factors appear to work to- gether with self-efficacy to facili- tate physical activity. Key words: urban, built envi- ronment, self-efficacy, physical activity, walking behavior Am J Health Behav. 2011;35(6):674-688 P romoting increased moderate-inten- sity physical activity to adolescents is a public health priority. 1,2 Studies show that physical activity in adolescence significantly predicts adult physical ac- tivity, and continuous physical activity at school age considerably increases the probability of being active in adulthood. 3 Furthermore, several studies have re- ported that there is substantial tracking of physical activity and weight status 4,5 from childhood and adolescence into later adulthood because childhood and adoles- cence are important stages to developing lifelong habits. 6 Walking is the most com- mon moderate-intensity activity for ado- lescents, and recent studies have dem- onstrated the potential of active transport to and from school to increase overall physical activity levels for both elemen- tary 7,8 and middle school students. 9 Trans- portation-related activity combined with other forms of moderate/vigorous physi- cal activity (PA) throughout the day has the potential to reduce the chronic health risks associated with an inactive lifestyle. Improved understanding of the correlates of walking and other forms of moderate/ vigorous physical activity can lead to evi- dence-based policies and programs. Off-school time provides a challenge and an opportunity for obesity interven- tions. Most school-based intervention projects have generally produced disap- pointing effects with respect to improving body composition. 10 Among the explana- tions postulated for why these obesity- reduction programs have not achieved their full prevention potential is that they fail to alter the environment in a way