Former UFC middleweight champion Rich Franklin has officially called time on his MMA career at the age of 40.

Franklin hasn’t actually fought since a first round KO loss to Cung Le in November of 2012, but had one fight left in his contract and up until this point he’d refused to rule out the possibility of returning to the Octagon one last time.

“I have to accept that I am no longer 25,” Franklin says of his decision. “The body has slowed down, and while ever so slightly, those fractions of a difference determine victory or defeat at the top level.

‘Ace’ was a fan-favorite in the UFC where he spent most of his professional career, winning the middleweight title against Evan Tanner in 2005 and successfully defending it twice before coming up against the man who would prove to be his nemesis, Anderson Silva.

Franklin had been on an eight-fight winning streak leading into their first encounter back in 2006, but lost by first round KO and again by TKO a year later.

While he never made it back to a title again after that Franklin remained a high-profile star who faced many of the biggest names in the sport at middleweight and light-heavyweight, beating the likes of Chuck Liddell, Wanderlei Silva (twice) and Yushin Okami while losing to other greats like Dan Henderson, Vitor Belfort and Forrest Griffin. In total he holds a 12-6 UFC record, 29-7 (+1nc) for his career overall.

Franklin remains involved in the sport of mixed martial arts as the Vice President of Asian promotion ONE FC, a position he’s held for over a year.