Yoo Jae Seok attracted attention with his muscular arm.
On August 3, a post titled, “Yoo Jae Seok during the shooting of Infinite Challenge” has been uploaded on an online community board.
Yoo and Haha are in the picture. Yoo is looking at his smart phone wearing a T-shirt and a bag pack. His muscular and sturdy arm amazed the viewers and attracted attention.
Netizens commented: “Yoo Jae Seok should challenge himself to Kim Jong Gook.” “Your muscular arms surprised me.” “You are a man!”
- Source: TV Report
K-STARS: 
Your the Best OPPA!
the unexpected muscular arm of yoo jae suk oppa is no joke. it’s jjang.
Saranghae jae seok oppa…ur the best!
Jae seok oppaa
… So so so perfect ….. ϊ’m gonna watching running man again XD …