TROY director Wolfgang Petersen instigated a bit of beefcake rivalry between Brad Pitt and Australian co-star Eric Bana on the set of the blockbuster, the pair revealed.

Petersen wanted his two leading men buffed like Chippendale dancers, and ordered both to the gym in an effort to bulk them up for the Ancient Greek epic.

Some mind games also came in to play, according to Pitt, whose physique has been idolised by women around the world for many years.

"He kept trying to pit Bana and I against each other," Pitt said of the German taskmaster.

"He kept saying 'Bana is looking really big' And I was like 'Stop, stop, we're working out. I'm in there every day, I'm suffering, it's miserable, I'm doing it'."

Bana underwent plenty of pain as well to sculpt his body into Hector, Prince of Troy, but the effort has been worth it. American reports suggest he is becoming something of a heartthrob himself.

Ask him what physical preparation he had to undertake and the former stand-up comedian says simply, "shitloads".

Bana didn't mind the gym work. It was mastering the Ancient Greek fighting skills and bareback horse riding that concerned him, although time was on his side.

Cast as Hector in September 2002, Bana had until the first day of shooting in March 2003 to work on it.

That meant plenty of training at home in suburban Melbourne swinging swords and riding horses.

"Learning the fighting skills, I'd never done any work with a sword before and also I was given plenty of warning about the horse riding," Bana said.

"Wolfgang said to me: 'Eric, you have to ride like the wind'."

"I'd never really ridden before, so luckily for me I had plenty of time to train for both, because I was cast back in September so I trained for months at home back in Australia before we got to London and continued the training every single day right up until when we wrapped."

Gyms were set up on the shoot locations in London, Malta and Mexico, and that fuelled the rivalry among the male actors.

"A lot of testosterone on set. Yes, a lot of testosterone," said Diane Kruger, a 26-year-old German supermodel cast to play Helen of Troy.

"There was lots of talk about horses. You know, 'My horse is better than yours' or 'Did you work out today?'."

The preparation for the actresses was the opposite - plenty of pizzas.

Kruger was ordered to put on weight because, apparently, 2700 years ago in Greece it was a sign of wealth for women to have extra curves.

The waif look was for the peasants.

"I had to gain it fast, in 15 days," Kruger- a model for Chanel and a former ballerina, said.

That meant a diet of protein shakes and pizza, and eating every two hours.

"I gained 12lb (5.4kg)," she said.

"It was fun for 24 hours, but that was it. A girlfriend of mine came to visit me and she actually lost 5lb because I had to eat so much. She was so disgusted, she was like 'Oh, another pizza?'."

Petersen was pleased with his curvy actresses and bulked up Pitt and Bana.

"What you see is body - it is actual, real muscle," Petersen said of his leading men.

"It was about really gaining so much more muscle and through very conventional (methods), working with weights in the gym and a special diet and with both."

Pitt, who often hides his looks in films, was a major project for the director. Petersen wanted beefcake.

"I remember our discussions early on when I said 'Brad, we all know that you do really like to try and hide you are such a good looking guy - not here," Petersen recalled.

"Here, you have to look the best Brad Pitt ever. The hair has to be nice and long and blond and your body, you have to train your body."