Found a link to this story on Dr. Michio Kaku's Facebook page. Inactivity can change the brain, and not in a favorable way.
http://well.blogs.nytimes.com/2014/01/22/how-inactivity-changes-the-brain/
http://well.blogs.nytimes.com/2014/01/22/how-inactivity-changes-the-brain/