The American Academy of Pediatrics' (AAP) position paper on “The Crucial Role of Recess,” describing the numerous benefits recess provides for children. The AAP recommends that all children partake in daily, supervised recess (AAP, 2013). Access to recess is important for all children, not only those who are typically developing but also those with special needs such as IDD. Minimizing or eliminating recess may be counterproductive to academic achievement, as a growing body of evidence suggests that recess promotes not only physical health and social development but also cognitive performance. Although recess and physical education both promote activity and a healthy lifestyle, it is only supervised but unstructured recess that offers children the opportunity to actually play creatively.
There is consensus about the need for regularly scheduled recess based on national guidelines, even though the length of the recess period has not been firmly established. In schools, the length specified for recess ranges widely, from 20 to 60 minutes per day. In other countries, such as Japan, primary school-aged children have a 10- to 15-minute break every hour, and this is thought to reflect the fact that attention spans begin to wane after 40 to 50 minutes of intense instruction.
http://pediatrics.aappublications.org/content/131/1/183