Ondřej Exler made his international debut in 2008 in Obertilliach as part of the IBU Cup and finished 112th in the sprint. In the further course of the season he improved to a 46th place in the sprint of Nové Město na Moravě , it is also his best result so far in the racing series. The first major event was the 2009 Biathlon Junior World Championships in Canmore . Exler finished 40th in the singles, 48th in the sprint, 56th in the pursuit and eleventh in the relay. A little later he also took part in the junior races of the 2009 European Biathlon Championships in Ufa , where he was 17th in the individual, 21st in the sprint and 20th in the pursuit. With the season he just missed a medal in fourth place. Later in the year launched Exler also in the junior race on roller skis of the Summer Biathlon World Championships 2009 in Oberhof and came up with the ranks 29 in the sprint, 31 in the pursuit and five in the relay. The results at the 2010 Biathlon Junior World Championships in Torsby were very mixed . In the individual he reached a very good fifth place, but in the sprint the Czech missed the pursuit race in 61st place by one place. The 2010 European Biathlon Championships in Otepää brought the results 19 in the sprint, 28 in the pursuit and individual and 14 in the relay. He contested the relay race with Vít Jánov , Tomáš Krupčík and Vlastimil Vávra in the men. At the Summer Biathlon World Championships 2010 in Duszniki-Zdrój Exler was 18th in the sprint, eleventh in the pursuit and eighth in the relay race.
In 2011 Exler also took part in these three international junior championships. First he started at the Biathlon Junior World Championships 2011 in Nové Město, where he reached 37th place in individual, 63rd place in sprint and eighth place in relay race. This was followed by the 2011 European Biathlon Championships in Ridanna , where Vavra was again 36th in the individual, 39th in the sprint, 38th in the pursuit and 12th in the relay. Again he was on the side of Lukáš Kristejn , Jánov and Krupčík for the men. At the 2011 Summer Biathlon World Championships in Nové Město, the Czech finished ninth in the sprint and was 14th in the pursuit race.
Czech Republic
Czechoslovakia
