Serious question: Why does Jennifer Lopez even bother going to the gym when wearing her massive engagement ring from fiancé Alex Rodriguez is surely workout enough? Seriously, that thing could sink a freakin’ cruise ship. On Wednesday, March 13, the “Dance Again” singer, 49, was spotted getting her sweat on in Miami with her new rock on full display. Scroll through the gallery below to see all of the over-the-top snapshots!