[1] Le Guellec began competing in the biathlon in 1999, and joined the national team in 2003.

He had significant success at the Junior World Championships, winning two medals in youth races at Haute Maurienne in 2004, and a bronze medal as a junior two years later in Presque Isle.

[2] His best career season on the Biathlon World Cup circuit came in 2008/09, when he finished 32nd in the overall standings.

His top finish in the Biathlon World Championships also came in Antholz-Anterselva, a 40th place in the 2007 individual race.

On February 14, 2010, he finished sixth in the men's sprint, which was the highest he had ever placed in any event up to that point.