I know, it's not something we all don't know but it's nice to see it in black and white. ASLA's blog LAND Connections posted a comprehensive explanation of why recess is so important in schools.
clear and unmistakable, through all the available research, that
children perform better, are more socially adept, and more physically
healthy when unstructured play is incorporated into school curriculum.
However, when discussing the topic of recess and breaks during
children's academic pursuits, there are still many avenues of research
left to explore. Issues such as bullying in the schoolyard, social
inclusion, childhood obesity, sensory integration, and inclusion of
natural elements are all very real and important topics needing
attention. As a start, let's let the children play!"