Four-time world champion Carl Froch announced his retirement from boxing on Tuesday after over a year out of the ring and said: "I think the desire has gone."
Super middleweight Froch, nicknamed The Cobra, twice won the WBC title, as well as taking the WBA and IBF belts, during a highly successful career.
The 38-year-old Nottingham fighter won 33 of his 35 fights, with 24 of those coming by knock-out.
He defeated arch-rival George Groves in a Wembley Stadium re-match which turned out to be his final fight in May of last year.
Froch said: "I'm incredibly proud of what I have achieved in boxing but now is the right moment to hang up my gloves.
"I have nothing left to prove and my legacy speaks for itself.
"I've got no regrets. I'm not retiring undefeated but in many ways that's better because I've boxed everybody, I've faced every challenge.
"So many athletes, not just boxers, don't get their defining moment. I've probably had seven or eight defining moments, but the biggest and best was on the platform of Wembley Stadium in front of 80,000 fans. It was amazing and to get that defining moment is enough."
Froch, who will become a boxing pundit, told Sky Sports News: "If I could fight again physically I would, but mentally I'm not sure. I think the desire has gone.
"There will always be options and it's never going to stop. There's always going to be somebody next in line or ready to try to take my scalp.
"And if that's never going to go away, at what point do you say, 'Right, now is the time to retire', based on challengers and opponents?
"You can't wait for that, it's got to be from within here, and as much as it hurts, and as hard as it is for me, and even making the decision to retire and saying it's been a year, it's too long, the fighting machine has gone, it's not going to come back, it's still hard.
"The last thing I think about before my head hits the pillow is boxing, and when I wake up in the morning to think what time it is, and I think it's half six, seven o'clock, should I be going for a run, where's my trainers - it's a lifestyle, a way of life, and it's a mindset. I'll always have that and I think I'll always be itching for the big fight."