Former Olympic champion hurdler Liu Xiang announced his retirement on his microblog on April 7, citing age and injuries 2 1/2 years after his last race. Liu became the first Chinese man to win an Olympic gold in athletics at the 2004 Athens Games in the 110-meter hurdles. He set a world record in 2006, and won at the world championships in 2007. The Shanghai native hadn't competed since withdrawing at the London Olympics in 2012 after rupturing his Achilles tendon. He pulled out of the 2008 Beijing Games with a similar injury. [Photo/Xinhua]