 Complete the following phrase:  Chambers returned to competition in June 2006 and won gold with his teammates in the 4×100 m at the 2006 European Championships. He tried other sports, including a spell with the Hamburg Sea Devils of the NFL Europa league and a rugby league trial with Castleford. Sprinting success came over 60 m when he won silver at the 2008 World Indoor Championships, gold at the 2009 European Indoors, and became world champion at the 