In case you missed it, this week Time Magazine has an article entitled, "Gym Class: Why kids' exercise matters less than we think." The article cites the information from last weeks blog post entitled, "Physical Activity : Is it influenced by Physical Education?"
The study and Time article questioned the value of physical education as an obesity intervention based on the research finding that the total weekly physical activity among children attending different schools was much the same despite large differences in the amount of time allocated to PE.
The researchers propose it's not the environment that drives physical activity levels in children, but some form of central control in the brain similar to appetite – an 'activitystat'.