He has already lost a lot of weight, but it appears he's kicking his fitness routine into overdrive now that he's set to walk down the aisle!

Rob Kardashian hit the gym in L.A. in this morning to work out with his trainer, and we have a feeling he's more motivated than ever to shed those last extra pounds before his wedding to new fiancee Blac Chyna. Kimmy K's little brother popped the question to his girlfriend last night with a $325K sparkler, and all signs point to a relatively short engagement given how fast these two have been moving in the romance department!

Tyga's baby mama has really brought the reclusive sock designer back from the brink, as he battled depression and eating issues for years before they got together. Rob's famous family reportedly recognized the makeup mogul's positive influence on him, so they were slowly coming around to the idea of them being a couple before news broke they plan on tying the knot. Tellingly, none of the K clan have taken to their social media accounts to send their well-wishes yet, so this latest development might not have gone over so well.

Rob seemed stressed as he drove away after his sweat sesh, and we wouldn't be surprised if Kris Jenner has been calling nonstop trying to talk some sense into her only son! After all, once he and Blac Chyna wed, she will legally be a Kardashian and allowed to use the name however she pleases!