Over a career spanning two decades, American Justin Gatlin has seen the highs and lows of track and field athletics.

Although he remains a controversial character in the sport, Gatlin is the most-medalled 100m runner ever at major championships, with three Olympic and five World Championship medals in the event.

As a college athlete, Gatlin was banned for two years for failing a test for amphetamines in 2001, later reduced to time served after appeal. The Brooklyn-born sprinter decided to turn pro after just two years in college, in preparation for the 2004 Olympic Games in Athens.

After coming second at the U.S. Olympic Trials and earning his spot on the team in the Greek capital, he went on to win the 100m in Athens – one of three medals he clinched at those Games.

He won his first world title the following year, clinching the 100m and 200m double in Helsinki. However, Gatlin would soon serve a second suspension.

In May 2006, the American broke the 100m world record. However, he was suspended at the end of July for having returned a positive doping test in April. Gatlin accepted an eight-year suspension, which was later reduced in half on appeal. The world record was annulled, and Gatlin did not return to athletics until 2010.