Donny Osmond Spills 'DWTS' Rehearsal Secrets

Donny Osmond has been working up a sweat rehearsing for "Dancing with the Stars," and he tells ET that his pro partner Kym Johnson is getting ready to really "crack the whip" on him!

"Kym is such a sweet person, she's really nice. She knows how to teach properly without really getting mad at ya, although she can be very stern, and very strict," Donny reveals. "She said she is going to crack the whip. Oh dear."

Donny says that though his first two dance rehearsals were a lot of fun, he's aching in muscles he didn't know he had -- but Kym's got the remedy!