f(x)'s Sulli shared her weight loss tips that she followed when trimming up for the group's latest comeback performance.
According to an article in Allkpop, Sulli attributes the 'plastic bag' diet for helping her get into shape.
Popular in Japan, the plastic bag diet consists of blowing up a plastic bag and continuously kicking it into the air using your knees or feet.
Netizens have commented that Sulli looks thin recently, and many have said that they would like to try the diet out.
Other guests also joined in and revealed their tips to toning up on the summer special episode.