When movie star Ewan McGregor flashes his biceps in the upcoming movie Son of a Gun, admirers can thank Bicton personal trainer Brett Smith.

Mr Smith, owner of Mind, Body & Soul fitness studio, worked with McGregor twice a week for five weeks to help maintain and develop his bad-guy physique for the movie, which has been mostly filmed in WA.

Mr Smith, who describes McGregor as "really normal", said his star client was a disciplined fitness fanatic. "He had three months of training in LA before coming to me, so he had good core strength," Mr Smith said.

"Certainly for his role playing a criminal he wanted the guns - the big arms - so he had to put on a bit of muscle and strength."

Mr Smith said McGregor's personal assistant came into the studio weeks before he arrived to ask questions on his behalf.

He believes his proximity to the star's temporary home in East Fremantle, and the fact his studio is a personal training centre and not a public gym, added to his appeal.
The personal trainer also revealed he managed to turn the Scottish star into a Dockers fan during his stay, taking the actor to Patersons Stadium for the round one derby win against West Coast.

McGregor tweeted today: "Heading to Melbourne today. Cheers Kalgoorlie. One week to go on #SonofaGun then home.''

Directed by local film maker Julius Avery, Son of A Gun tells the story of a seasoned criminal returning to the underworld for one last score.

Much of the shooting in Perth was at the now dilapidated Sunset Hospital in Nedlands, before moving to the historic gold mining town of Kalgoorlie and then Melbourne.

McGregor kept a relatively low profile while he was in Perth, popping up at the launch of Polo in the Valley and watching the Western Derby, cheering on the Dockers on Twitter after they won.

But he tweeted many photos from the Kimberley region, describing the Kununurra landscape as "amazing''.

Tourism WA chief executive Stephanie Buckland said McGregor chose the Kimberley when the government agency offered him opportunities to explore part of the state.

"When someone with a high profile is in Western Australia, Tourism WA will, where possible, try to maximise the opportunity, offering them the chance to tour part of the state,'' she said.

"The advantage of having celebrities endorse the state is the publicity their visits can attract and WA is beginning to develop a cult celebrity following.''

Famous visitors to WA have included Jerry Hall, Kelly Slater, Nicole Kidman, Tom Cruise, Miranda Kerr and Mel B.

Ms Buckland said films were a great way to promote a destination.

"It has a lot more impact when people can get engaged in a movie and fall in love with it - then they want to see the destination,'' she said.

"Rather than just seeing an offer on a brochure, if you can make that emotional connection, it's a lot more likely to be successful.''

Films shot in the state include Australia, Red Dog, Bran Nue Dae and Drift, which was shot in the state's South West surf region and will be released in May.

After Australia was released, the Kununurra and Broome visitor centres reported their highest ever numbers, Ms Buckland said.