Justin Gatlin announced his retirement from athletics on Thursday, hanging up his spikes after a career tinged by doping controversies that included an Olympic gold medal and multiple world titles. The 40-year-old veteran, who won gold in the 100m at the 2004 Athens Olympics, confirmed his retirement in a post on Instagram titled "Dear Track." "I have loved you track. You gave me tears of sadness and of joy, lessons learned that will never be forgotten," Gatlin wrote. "The torch is passed but the love will never fade. On your mark, get set ... Gone!" Gatlin's retirement had long been expected. He had attempted to qualify for the Tokyo Olympics last year but suffered a hamstring injury at the US trials in Eugene. He completed a 100m and 200m sprint double at the World Championships in Helsinki in 2005, and also won 100m gold at the 2017 Worlds in London, scoring a rare victory over Jamaican icon Usain Bolt in the process.