Justin Gatlin, the talented but polarizing American sprinter, announced his retirement on Thursday (February 10), coinciding with his 40th birthday.

Gatlin, the 2004 Athens Olympic 100m champion, was World 100m World Champion in 2005 and 2017, eventually became Usain Bolt’s greatest nemesis, during a career tainted by a couple of anti-doping suspensions, the last of which was reduced from a potentially career-ending eight-year ban imposed 2006.

He had been mulling retirement after suffering an injury at the 2021 US Track and Field Championships and failing to qualify for the USA team to the Tokyo Olympics.

During an interview late last year, he said he would have made a decision close to a return to pre-season training. That decision was delayed until Thursday when he announced 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!”

After coming up short against Bolt in the World Championships 100m final in Helsinki in 2015, Gatlin finally managed to defeat Bolt at the 2017 World Championships, to win a second title.

He was also part of the USA’s gold-medal-winning 4x100m relay team at the Doha World Championships in 2019.

Gatlin was banned in 2001 after testing positive for Adderall and then again in 2006 when his sample showed high levels of testosterone in his system.