Excercise is linked to better learning. Not that surprising. I was, however, surprised that stimulating environments didn't have an impact unless physical excercise was present.
http://www.nytimes.com/2012/04/22/magazine/how-exercise-could-lead-to-a-better-brain.html?_r=4&pagewanted=1&seid=auto&smid=tw-nytmag