Reducing sedentary behavior: the relationship between park area and the physical activity of youth.

This study was designed to determine whether the characteristics of the neighborhood environment are related to the substitution of physical activity for sedentary behavior among youth. Fifty-eight 8- to 15-year-old youth were studied in a within-subjects crossover design with three phases: baseline, increased sedentary behavior, and decreased sedentary behavior. The relations between changes in physical activity and design, diversity, and density attributes of the neighborhood environment were determined using random coefficient models. Compared with girls, boys showed greater increases in physical activity when sedentary behaviors were reduced and greater decreases in physical activity when sedentary behaviors were increased. Greater access to parks was associated with greater physical activity when sedentary behaviors were reduced.