Leccardi, who competes for the Gardes Frontières, has been taking part in competitions organized by the Fédération Internationale de Ski since 2000 . At the Junior World Championships in 2002 he was 64th in the sprint and 65th over 10 kilometers in the free technique. In the following year he improved to 22nd place in the sprint at the Junior World Championships in Sollefteå, Sweden , and to 40th place over the 10 kilometers, which this time were carried out in the classic technique. At his last Junior World Championships in 2004 in Stryn , Norway , he achieved his best individual result at the Junior World Championships with twelfth place over 30 kilometers in the classic technique. After he finished 28th in the free technique and in the sprint over 10 kilometers, he was also used in the Swiss 4 x 10 kilometer relay, which finished eighth. He ran his first World Cup race in October 2006 in Düsseldorf , which he finished in 63rd place in the sprint. In February 2008 he got his first World Cup points in Otepää with the 21st place in the sprint. At the Nordic World Ski Championships in Liberec in 2009 , he finished 31st in the sprint and 16th together with Christoph Eigenmann in the team sprint. In February 2010 he achieved his best individual result in the World Cup with 15th place in the sprint in Canmore . That same month he came in at the 2010 Winter Olympics in Vancouver on the 38th place in the sprint. At the Nordic World Ski Championships in 2013 in Val di Fiemme , he achieved 37th place in the sprint. Since 2009 he has also participated in competitions of the Australia / New Zealand Cup . In 2014 , he took first place in the overall ranking. In 2010, 2014, 2015, 2018 and 2019 he won the Kangaroo Hoppet , which makes him the record winner. He also won the Gommerlauf over 42 km in 2014 and 2015 .
Leccardi has competed in 40 individual World Cup races so far and has made it into the points eleven times in the sprint. So far, he has won 18 medals at Swiss championships. He was Swiss champion five times with the Gardes Frontières relay.