II. Physical activity: measurement and behavioral patterns in children and youth

With physical activity levels among children and adolescents at an all-time low, there is a critical need for scientists and public health officials alike to further examine the physical activity behaviors of this population. Accordingly, this chapter will act as an entrée to the rest of the monograph by providing a general overview of the epidemiology of physical activity among youth in the United States. In so doing, we discuss the following: public health guidelines for youth-based physical activity, current rates and trends of physical activity participation in youth, issues related to physical education rates in school systems, lifestyle practices that encourage sedentary behaviors and attendant disease states, a synopsis of the health-related benefits of a physically active lifestyle, promotion of and opportunities for increased engagement, and comparisons of objective and subjective methods of measuring physical activity.