There are neurological effects as well. Serious research should be done on whether children with attention deficit disorders, other learning disabilities and behavior problems are actually presenting symptoms of overall motion starvation. We must know if these kids need doses of drugs or doses of recess. More motion might be a better option for school districts considering latter class starting times for teen-agers who are said to have a biological predisposition for staying up late and sleeping longer in the morning. I may be missing something, but it seems to me the only relevant biological predisposition at issue is the one violated by the invention of the light bulb.
Teens go to malls and movies, watch TV and ram around in cars for enough stimulation to get tired.
I find that attitude, behavior and education problems in youngsters increase or decrease in direct relation to how much physical activity they are allowed. It is not a matter, however, of merely burning off excess energy. Modern technology has eliminated most naturally occurring stimuli that kept are ancestors limber, strong and healthy. This has to be replaced in some way. For adults it takes regular motion-intense program that moves muscles that are not being regularly engaged.