Richmond, T. K., Hayward R. A., Gahagan, S., Field, A. E., & Heisler, M. (2006). Pediatrics, 117(6), 2158-2166.

Physical activity is recognized as a potentially modifiable behavior that may prevent or reduce the risk of overweight. Accumulated data indicate racial/ethnic disparities in adolescents' levels of physical activity; however, less information is available on the causes of these disparities. This cross-sectional analysis of 17,007 adolescents in wave 1 (1995) of the National Longitudinal Study of Adolescent Health (Add Health) was designed to examine social attributes of school environments, including school income and racial/ethnic composition, and their potential to modify the association of race/ethnicity with physical activity. It is noteworthy that participants attended racially segregated schools; 80% of Hispanic and black adolescent boys and girls attended the schools with populations having less than 66% white adolescents, and nearly 40% of white adolescents attended the schools that had more than 94% white adolescents. In addition, black and Hispanic adolescents attended the schools with median incomes that were substantially (P < .001) lower than the median incomes of the schools attended by white adolescents. The results indicated that black adolescent girls engaged in physical activity 0.46 fewer times per week than white girls (P < .001) and Hispanic girls engaged in physical activity 0.29 fewer times per week than white girls (P = .12). When school-level characteristics were included in the analysis, race/ethnicity was no longer independently associated with physical activity (P = .13 for black and P = .70 for Hispanic race/ethnicity, respectively). Specifically, school-level median household income of the student population (P < .001) was predictive of girls' physical activity participation; however, the schools' ethnic composition was not predictive (P < .15). In contrast, in adolescent boys, results indicated that Hispanic adolescents engaged in 0.34 more activities per week than white adolescents (P = .008); no differences were observed between black and white adolescent boys. Similar to girls, age was strongly associated with physical activity levels; younger adolescent boys self-reported physical activity more times per week than their older counterparts. Both the racial composition of the school (P = .01) and the school-level median household income (P = .001) were predictive of adolescent boys' physical activity participation.

These results emphasize the importance of social characteristics of school environments as contributors to the observed racial/ethnic disparities in adolescent physical activity. Clearly, future research is required to determine the mechanisms through which school-level associations are mediated so that effective interventions and policy changes can be developed with the goal of increasing participation in physical activity, especially for youths in low-income communities. As the largest group of healthcare professionals, nurses can be instrumental in advocating for resources necessary to inform and guide effective interventions and the policy changes necessary to reduce racial/ethnic disparities in this important behavioral determinant of health.

Laura L. Hayman