“The rehearsal schedule is grueling but I’ve been really enjoying the workout aspect of it. It’s four hours a day for six days a week,” the Glee star, 27, told PEOPLE at the Tadashi Shoji fashion show at Lincoln Center in N.Y.C. on Thursday.
Riley will appear on the 17th season of the show, which premieres Sept. 16, with dance pro Derek Hough.
“He is so cute and so sweet and he actually reminds me of Chord [Overstreet]” who plays “trouty mouth” Sam Evans on Glee.
Hough has already won the competition four times which helps ease some of Riley’s nerves.
“When I found out he was the person I was going to be dancing with it boosted my confidence a little bit, so I’m really excited about it,” she adds.
Riley is no stranger to the stage as a powerhouse singer, but being apart of a duo instead of an ensemble is unfamiliar territory for the star.
“I’m used to having 11 other people around me camouflaging my bad dancing,” she jokes. “Now it’s me and Derek.”