http://news.bbc.co.uk/sport1/hi/boxing/7871918.stm Undefeated world super-middleweight and light-heavyweight boxing champion Joe Calzaghe has announced his retirement. The 36-year-old Welshman, who reigned as a world champion for more than 11 years, quits the ring with a glittering record of 46 wins from 46 fights. "It was a difficult decision but I have achieved everything I wanted to achieve in boxing," he told BBC Sport. "I've been world champion for 11 years. I've got no other goals to go for. That's why I am calling it a day." In an exclusive interview with BBC sports editor Mihir Bose, Calzaghe, who held the WBO, WBA, WBC and IBF super-middleweight belts during his 16-year professional career, said he had thought "long and hard" about retiring but insisted it was the right move. "I had a long think with my family," he said. "My children wanted me to give up, plus my mum. That's why I called it a day and will go on to do something else."