He has achieved world first level rankings in the under 68 kg weight class.

Lee grew up practicing martial art at his father's taekwondo academy from age 5.

[4] Lee made his international flyweight debut at the 2011 World Taekwondo Olympic Qualification Tournament in Baku, Azerbaijan where he had his first international loss to 2008 Olympic silver medalist Gabriel Mercedes 14–12 in the semifinals.

At the 2016 Summer Olympics Lee won a bronze medal, beating Jaouad Achab from Belgium 11–7.

[7][8] In 2016 WTF World Taekwondo Grand-Prix, Lee won gold against Konstantin Minin.