[1][2] He won a bronze medal, as a member of the South Korean swimming team, in the 400 m freestyle relay at the 2010 Asian Games in Guangzhou, China.

Jung qualified for two swimming events at the 2012 Summer Olympics in London, by eclipsing FINA B-standard entry times of 2:02.50 (200 m individual medley) and 4:18.98 (400 m individual medley) from the FINA World Championships in Shanghai, China.

[3][4] In the 400 m individual medley, Jung challenged seven other swimmers on the second heat, including two-time Olympian Raphaël Stacchiotti of Luxembourg.

He clinched a fifth spot and twenty-eighth overall by six hundredths of a second (0.06) behind Belarus' Yury Suvorau and Portugal's Diogo Carvalho, outside his entry time of 4:23.12.

[5] In his second event, 200 m individual medley, Jung edged out Ukrainian swimmer and double European junior champion Maksym Shemberev of Ukraine to claim a heat one victory by 0.07 of a second, with a time of 2:03.33.