A.O.
As a former competitive gymnast and now coach, gymnastics would be great for your son. It teaches discipline, body awareness, team work, the list goes on. My brother was also a competitive gymnast and competed for the University of Oklahoma and is now a head coach at one of the top programs in Oklahoma. I have 3 children and the older 2 are taking classes right now, my son who is 3 just enjoys playing around but my 2 year old daughter is advancing quite rapidly and loves it. I would highly recommend it and with the olympics right around the corner you could get your son excited by watching the mens competition.