Alexei Katrenko was a particularly successful summer biathlete as a junior. At his first Junior World Championships in 2005 in Muonio , he won gold in the mass start and relay, silver in the pursuit and bronze in the sprint. A year later in Ufa , after bronze in the sprint, he won the gold medal in the pursuit and with the mixed relay. He has started in the senior sector since 2007 and has been able to continue his successes there as far as possible. At the World Championship of the year in Otepää , he won the mass start and relay titles and bronze in the sprint. At the 2008 Summer Biathlon World Championships in Haute-Maurienne , he won the sprint and pursuit titles. His start in the sprint of the roller ski competition brought only 36th place. At the 2009 Summer Biathlon European Championships in Nové Město na Moravě , he won the title with Tatiana Belkina , Ljudmilla Solomatina and Alexander Katschanowski and the silver medal in the sprint. A year later , Katrenko again won gold and silver at the Summer European Championships. He won gold alongside Irina Leukhina , Olga Prokopewa and Maxim Adiew , in the sprint he missed a medal by 1.4 seconds in fourth place. In the pursuit race he improved to second place behind Matej Kazár .