From Kazakhstan Encyclopedia
Alexanin began fencing in 2002 at the instigation of his mother. His first coach was Igor Yarmolkevich. He was then placed under the responsibility of national épée coach Valery Dimov. He made his international debut in the 2010–11 season at the Legnano World Cup. A year later, he won the bronze at the Trophée Monal.
At the 2012 Summer Olympics he competed in the Men's épée, but was defeated in the first round by Silvio Fernández. He won a team bronze medal with Kazakhstan at the 2013 Summer Universiade. He reached the quarter-finals in the individual event and won a team gold medal at the 2013 Asian Fencing Championships in Shanghai. At the 2013 World Fencing Championships in Budapest he reached again the quarter-finals, where he was defeated by Estonia's Nikolai Novosjolov who eventually won the gold medal. Alexanin finished the 2013–14 season No.25, a career best.
Alexanin studied at the Kazakh Academy of Sports and Tourism. His elder brother Sergey is also a fencer.