On the latest airing of 'Ranking Show' on December 22, a stunt model who works as a double for many underwater scenes in the K-entertainment industry appeared as a guest.

The stunt model, who was once a national champion in synchronized swimming, confirmed that she was a former double for top celebrities such as Jun Ji Hyun and AOA's Seolhyun.

SEE ALSO: Na In Woo addresses his exemption from mandatory service during 'Motel California' press conference

Even for the underwater sequences of the drama "The Legend of the Blue Sea," the guest took on the role of the main figure, Shim Chung. The stunt model revealed that she has perfected a way to hold her breath for up to 1 minute and 43 seconds.

However, underneath all the glamour, the model expressed that it takes tremendous effort to maintain the same lean body figure as that of the actresses. To do her job, she had to strictly control her diet on many occasions.

The goal for this week's episode was to rank models in the order of 'Most Experienced' to 'Least Experienced.' One of the celebrity guests who also appeared as a model was Ren of NU'EST.