The JHJCR has lots of sports teams and societies that you may join. The sports team compete between different colleges giving you the freedom of playing the sports you want to at a level that's cloeset to your own.
Along with the sports teams their are societies that you may also join for people that have simalar interests to you; there's everything from the "Neighbours Society" to the "Ladies Group". And just in the outlandish case that there isn't a society to fill your every need, you can start your own.