The popular K-pop singer/rapper/producer put her athleticism on display in a new Instagram post ... rocking athletic wear, white boxing gloves and some cat-themed headgear as she worked on some combos.

The 26-year-old even throws a knee at one point ... proving she isn't afraid to use more than her hands.

Naturally, the idol's fans all had similar reactions to the clip ... with many joking about how the vicious punches were a message to her agency, Cube Entertainment, which she is rumored to leave when her contract expires this month.

Soyeon is no stranger to Chan Sung Jung's training facility -- not only does she train there, she also got his whole crew to break out the choreography to the group's new song back in July.

Of course, Korean Zombie was a staple in combat sports for more than a decade ... before deciding to retire from his professional career in 2023.