Schools have played a central role in the provision of physical activity to American children and youth for more than a century. Physical education (PE) has been an institution in American schools since the late 1800s,1 and school sports have been a growing component of the educational enterprise since the early 1900s. Traditionally, students have engaged in physical activity during recess breaks in the school day and by walking or riding bicycles to and from school. However, as we move into the 21st century, alarming health trends are emerging, suggesting that schools need to renew and expand their role in providing and promoting physical activity for our nation’s young people.