Shane Carwin has had enough.
The 38-year-old engineer by day has announced his retirement from MMA. Carwin finished his career 12-2 and is a former interim UFC heavyweight champion.
Officially retired 2day:-) thank you to my family, friends and fans! #dreambig GOD BLESS!!!
— Shane Carwin (@ShaneCarwin) May 8, 2013
Carwin has underwent neck, back and knee surgery since 2010, and has not fought since a loss to Junior dos Santos in 2011. He served as a coach on The Ultimate Fighter late last year, but was forced out of a planned bout with Roy Nelson.