Observed environmental features and the physical activity of adolescent males

Background: It has recently been reported that adult physical activity was associated with environmental features. The aim of this study was to determine whether environmental features were associated with physical activity among male adolescents. Methods: Physical activity levels of 210 Boy Scouts were assessed for 3 days by accelerometry during 2003 and 2004. Mean minutes of sedentary, light, and moderate-to-vigorous intensity activity were calculated. Environmental features within a 400-meter radius of each participant's home address were assessed by direct observation using the Systematic Pedestrian and Cycling Environmental Scan (SPACES) instrument. Principal component factor analysis reduced the 35 SPACES items to four factors. Hierarchical and spatial regressions were conducted with physical activity as the dependent variable and environmental factors, age, body mass index, and ethnicity as independent variables. Results: Four factors were obtained: walking/cycling ease, tidiness, sidewalk characteristics, and street access and condition. Sidewalk characteristics were negatively associated with minutes of sedentary behavior while age was positively associated. Sidewalk characteristics were positively associated with minutes of light-intensity physical activity and age negatively associated. No environmental factor correlated with moderate-to-vigorous physical activity. Conclusions: A sidewalk characteristics factor, composed of sidewalk location, sidewalk material, presence of streetlights, and number and height of trees, was positively associated with light-intensity physical activity among male adolescents.