Peter Facinelli competes with his 'Twilight Saga' co-stars over who can spend most time at the gym.

The 36-year-old star - who plays Dr. Carlisle Cullen in the vampire movie franchise - admits there is an "unspoken competition" between the actors over who can get the fittest.

He told BANG Showbiz: "We had this kind of unspoken competition between all of us. Working out is addictive enough and then you have all the cast members working out.

"Not so much to get buff, my character doesn't need to look like Kellan Lutz's character but we had to be fit to do the fight training. But everyone was always in the gym - whenever you wanted to find somebody you just headed to the gym."

Peter confesses the competition became so intense he once caught Kellan - who plays Emmett Cullen - doing press-ups while waiting for an elevator, leading him to give up the fight.

He said: "I remember going down to the gym and the elevator doors opened and Kellan Lutz was on the floor doing push ups waiting for the elevator and then I just put my hands in the air and said, 'Ok, you win.' I just went back to my hotel."