HaHa opened up about how 'Running Man' physically drains the members. 

On May 22, YouTuber Korean Englishman uploaded a video featuring HaHa. While having a Korean BBQ with soju, Korean Englishman mentioned the popular variety show and asked, "You guys have fun filming it right?"

HaHa got honest and replied, "There are times when it gets tough. Seriously... It's gonna be silly if I call it 'off the record' and say it myself but I'll just say it. Everyone got slipped disks while filming that show. Everyone's suffered herniated disks."

He continued, "Jong Kook hyung was first then Jae Suk hyung. He had disk problems before but despite his condition, he kept on filming till the end. Kwang Soo went home after filming and was found in his bed with the herniated disk the next day. And his manager had to carry him to the hospital... Everyone's got disk operations. Surgical procedures."

HaHa added, "Seriously, everyone's got health issues. We need rehab treatment but we don't have the time," and said, "We've been doing this together for 10 years now. Filming the show is of course so much fun but we have this sort of comradeship now. We're comrades now in a way. We're always like 'Let's do this!'"

You can watch HaHa with Korean Englishman in the clip below.