[2] His first sport, basketball, left him frustrated as he seldom got to touch the ball, so his mother took him to the fencing section of Sokol Brno when he was eight.

At the age of 17 he aimed for the 2012 Summer Olympics in London, but he was defeated by Romania's Radu Dărăban in the quarter-finals of the qualifying tournament in Bratislava.

At the beginning of the 2013–14 season Choupenitch transferred from Sokol Brno to CS Fides in Livorno, Italy, to train under Paolo Paoletti.

[10] In the European Championships at Strasbourg, he reached the quarter-finals, but was defeated 13–15 by Great Britain's James-Andrew Davis, who eventually won the gold medal.

In the 2014–15 season Choupenitch won a silver medal at the Shanghai Grand Prix, losing in the final to the USA's Miles Chamley-Watson.