A depressing study by the National Institutes of Health (NIH) revealed Wednesday that kids’ activity levels drop dramatically between the ages of 9 and 15, with the majority of children failing to meet their daily recommended activity levels.

The Department of Health and Human Services recommends that kids be active for at least an hour every day – walking, jogging, cycling, swimming, basketball, etc. The NIH’s long-term study showed that at 9 years old, children average around three hours of “vigorous physical activity” each day, but by 15, kids are averaging only 49 minutes during weekdays and 35 minutes on weekends.

Some of the study’s suggestions to help kids be more active included encouraging local government officials to offer biking and walking trails for kids to use to get to and from school each day. They also encourage families to take evening walks together and weekend bicycle rides.

Commenters on this story at ABC News suggested that kids spend too much time playing video and computer games, and also that kids need to do more house and yard work. The Chicago Tribune also attributes the problem to schools dropping recess. But what about where we live? Smart Growth America has repeatedly linked suburban sprawl to lack of activity, obesity and other health programs to children and adults. They affirm that people need to live in communities designed to be walkable and that foster easy ways to sneak in physical activity. It isn’t enough to blame kids’ laziness on Nintendo; we have to think about why kids can’t, or don’t, go outside anymore.