PE programs vary greatly, and that allotted time for classes ranged from 30 minutes to 150 minutes per week, Friedman adds.
"It's another piece of evidence that young children don't get the exercise they need," Friedman tells WebMD. "It is a call for action. Children are developing a lifestyle that is not good for their health. If children don't learn about the importance of exercise and enjoy exercise when they are young, they will not pick it up later."
Not shocking data at all, especially in urban settings, says King. "With the epidemic of violence, the crises in school budgets, we have seen the opportunities for kids to be outside and exercise -- in neighborhoods and schools -- virtually vanish," he tells WebMD.
In North Philadelphia, the average school might house 500 kids, and have only about 1000 square yards of blacktop area for recess, he explains. An indoor room serves as gym, assembly room, and cafeteria from 10 a.m. to 2 p.m. -- the majority of the school day. "Compare that to a rural or suburban school where they may have five to10 acres of grass," King says.
Also, budget cuts have impacted school programs. "PE is one of the first cuts made, and one of last programs to come back," he adds.
"It's frustrating -- there are acres and acres of abandoned land, empty apartments, in the major cities. In a dense city like Philadelphia, they're within blocks of the schools. It just takes some grass seed, literally a grass-roots effort, to transform these areas into exercise space for kids."