Shane Carwin quickly rose through the UFC heavyweight ranks, earning himself the interim title.

Just as quickly, Carwin’s body started disagreeing with him, forcing the engineer to retire from MMA recently.

Neck, back and knee issues were just some of the ailments that hampered Carwin, went 12-2 in his career, last fighting in 2011.

“I felt like a weight had been lifted off my shoulders because it has been a struggle these last two, three, four years being in pain all of the time,” said Carwin, in an interview with Sports Illustrated. “MMA taught me a lot about myself. I was definitely meant to be a fighter in the cage. Don’t get me wrong. I loved the game of football. I still drive by the grass fields in the fall and smell that smell and it brings back memories, but being able to go one-on-one? That’s you. That’s 100 percent you. Anything you do in there is from your heart and mind. I think it’s the truest sport in the world today, as true as a competition can be in finding out who the best man is.”

Carwin added that giving up the sport he trained “since he was six” was very difficult, but he knew it was time.

Kudos to Carwin, who listened to his body and didn’t put any further wear or tear on it. Hopefully he enjoys retirement.