Children are not meant to be sitting down and studying for 7 hours a day! Recess time has shrunk to almost nothing, gym is often culled if other 'more important' events need to take place and then children are penalized for having too much energy.
Schools need to incorporate multiple breaks for the children throughout the school day. Learning does not occur only at the student desk. Our elementary school recently shortened lunch and recess time to get 10 more minutes of teaching time into the school day! this is not something our schools should be proud of. Physical movement and socialising wakes up the brain as well as the body and is something essential for everyone - old or young.