Six months earlier he had qualified for the Olympic Games in Sydney, but lost his fight to future middleweight champ Jermain Taylor.

On 13 September 2003, he replaced the injured Bert Schenk in a WBO title bout against Argentinian Hectór Javier Velazco and won the match.

On 5 June 2004 in Las Vegas, Sturm faced Oscar De La Hoya in a defense of his WBO middleweight championship.

Sturm defeated Lorenzo by a twelve round unanimous decision with the judges giving a comfortable 117-111 twice and 118-111 on the scorecards.

After defeating top contenders Matthew Macklin and Sebastian Zbik, Sturm lost his WBA title to Australian Daniel Geale.

Sturm broke the silence two months later with a post which he shared via Instagram where he complained about being treated unfairly by the doping investigators.

Sturm wrote that he was only informed two months after the first doping sample about the results and that he wasn't told why it took longer than usual (two weeks).

Sturm dominated opponent Timo Rost throughout the fight and earned a unanimous decision victory, winning wide on all three scorecards.

His parents, Ćamil and Zahida, are ethnic Bosniaks who hail from Blagaj, Bosnia and Herzegovina, having emigrated to Germany in the 1970s.