He became a stagiaire for Cofidis in 2003 before turning professional with the Vlaanderen–T Interim team in 2004.

He crashed on the 18th stage and was forced to abandon with a broken collarbone.

[2] Despite these promising results on the road, Gadret was back in the 2006–2007 cyclo-cross season where he challenged the domination of Belgian Sven Nys in the Koppenbergcross[3] and finished 8th in the UCI World Cyclo-cross Championships.

[6] On Stage 15 of the 2010 Tour de France Gadret caused controversy when he refused to give his wheel to his team leader, Nicolas Roche, following a puncture on the final climb of the day and then began attacking the group ahead of Roche.

He was unable to secure a professional contract after the 2015 season, and returned to the amateur ranks.