Physical activity among adolescents. When do parks matter?

BACKGROUND The availability of places to engage in physical activity may influence physical activity levels. This study examined whether the relationship between physical activity and access to parks differs depending on adolescents' sociodemographic, housing, and neighborhood characteristics. METHODS Data were analyzed from 4010 adolescents who responded to the 2003 California Health Interview Survey (CHIS). Analyses were conducted in 2005-2006. Five sets of logistic regressions were conducted to examine the relationship between physical activity and access to a safe park among adolescents living in (1) urban versus rural areas; (2) apartment buildings versus houses, (3) neighborhoods perceived as unsafe versus safe; (4) lower- versus higher-income families; and (5) adolescents who were Latino, African American, Asian, or white. Analyses also examined interactions between park access and these factors. RESULTS Access to a safe park was positively associated with regular physical activity and negatively associated with inactivity for adolescents in urban areas, but not rural areas. Additionally, adolescents with access to a safe park were less likely to be inactive than those without access among those living in (1) apartment buildings, (2) unsafe neighborhoods, and (3) lower-income families. Park access was not associated with regular physical activity for these groups. The association between park access and physical activity varied by race/ethnicity. CONCLUSIONS These findings suggest that the relationship between physical activity and access to parks differs depending on adolescents' sociodemographic, housing, and neighborhood characteristics, and that parks may be particularly important for promoting physical activity among urban adolescents.