Wang, along with co-authors Shiru Li, MD, MS, former visiting scholar with the Bloomberg School's Center for Human Nutrition, and Margarita Treuth, PhD, adjunct associate professor with the Bloomberg School's Center for Human Nutrition and a professor with the University of Maryland East Shore, examined findings from the nationally representative Youth Risk Behavior Surveillance (YRBS) surveys from 1991 to 2007. The survey included U.S. high school students in grades 9 through 12 and provided information about their physical activities including enrollment and participation in physical education in school and sedentary behaviors including screen time. Based on these surveys, researchers examined the patterns and time trends and compared the observed physical activity patterns with the national goals set in Healthy People 2010, a comprehensive agenda for improving the health of all Americans. They found that minority students were less likely to be physically active and more likely to engage in sedentary behaviors than white students. Girls were less active than boys and decreased physical activity was related to an increase in age.

"The large gaps between the 2007 achievement and the 2010 targets indicate that the goals are unlikely to be achieved by 2010," said Wang. "Our study suggests that more vigorous efforts are needed to help young Americans engage in adequate regular physical activity and reduce sedentary behaviors, which will help promote good health. In addition, these findings may suggest factors other than physical activity, and sedentary behaviors such as unhealthy eating may play a more important role to help explain the recent increase in obesity."

"How Active are American Adolescents and Have They Become Less Active" was S. Li, M.S. Treuth and Y. Wang.

The research was supported in part by research grants from The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) and The Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD).

Source: Johns Hopkins University Bloomberg School of Public Health