The 'Running Man' cast attempted idol choreography on last week's 'Idol Special' episode, and an unseen behind-the-scenes clip has now been revealed of their practice.

SBS tweeted on the 12th, "Last week's fabulous 'Running Man' opening was possible because of a rapid course. We're sharing a short clip of the dance practice that didn't make the air."

On the September 8th broadcast, Lee Kwang Soo-MBLAQ, HaHa-INFINITE, Gary-A Pink, Yoo Jae Suk-Girl's Day, Kim Jong Kook-SISTAR, and Ji Suk Jin-2PM teamed up to open up the show with dance performances. 

SEE ALSO: Gary and A Pink perform as 'Gary Pink' on 'Running Man'

Netizens who've seen the clip above commented, "The cast really worked hard on the dances," "I have to rewatch these," and "As expected, the 'Running Man' cast members are a delight."

Check out the BTS clip above, and rewatch all the intro dances below!