Tom Cruise admits that he gets "tired" when he performs too long.

Mission: Impossible - Ghost Protocol actor is a huge fan of entertainers.

In preparation for his role as character Stacee Jaxx in upcoming film Rock of Ages, Tom had to croon and put on his dancing shoes for extensive periods of time.

Tom is impressed by people with the stamina to sing and dance.

"You know, dancing... my hat's off to all dancers. I think they're the best athletes in the world, those guys," Tom told Extra.

"Even singing, I had no idea... I'd do two or three hours singing and I'd go, 'Man, I'm a little tired.'"

Tom consulted rocker Jon Bon Jovi for singing advice during filming.

"I said, 'Man, I'm gonna sing your song,' and [Bon Jovi] just looked at me and said, 'You know what to do.'" Tom recalled.

Although he may not want to train to become a dancer anytime soon, Tom believes that he is in good shape for his age.

"I'm gonna be 50... July 3rd," he revealed.

"No sleep. Three kids... you gotta go, go, go!"

Rock of Ages will be released in 2012.