"While some elementary schools no longer have recess, and people like New Jersey Governor Chris Christy argue that school days should be longer, a few schools are already moving in a different direction. Some are testing outstanding desks, and realizing that a little bit of activity can actually improve attention spans Others, like Ward Elementary in Winston-Salem, North Carolina, are starting to fill classrooms with exercise bikes, so students can work out while they learn."
https://www.fastcoexist.com/3036607/this-school-has-bikes-instead-of-desks-and-it-turns-out-thats-a-better-way-to-learn
Biking in Baltimore