I notice you’ve referenced Infinity Challenge (Muhan Dojeon), Episode 346, with “Eng Su” likely meaning English subtitles.

Furthermore, the episode permanently changed the cast. Noh Hong-chul, who was often the "weird" member, proved he had incredible physical comedy chops. Park Myung-soo’s "Myung-soo-nonna" became a cultural icon, referenced in dramas and other variety shows for years. Infinity Challenge Ep 346 Eng Su

: This episode captures the intense and often comedic physical training the members underwent to master complex cheer routines, highlighting the show's signature "challenge" spirit. Guest Appearances The captions read: “7 days since the 24-hour relay race

If you’d like, I can:

Finding a "solid piece" or full viewing copy of this episode with English subtitles is notoriously difficult for modern fans. who was often the "weird" member

The captions read: “7 days since the 24-hour relay race.” “Bodies broken. Spirits shaken.”