Percy Jackson star Logan Lerman had to grow up fast when filming his new movie Fury.
The 22-year-old actor was asked to fight with his co-stars during a week-long boot camp that preceded the main shoot.
"We fought a lot," he says. "I really hated the fighting at first. The other guys are all a fair bit older than me and are more experienced and in better shape.
"And because I'd broken my arm not long before shooting began, I got my a** kicked every day," says Lerman, who plays a rookie member of an American tank crew, commanded by Brad Pitt, during the last days of World War II.
"I went in there thinking, 'I'm not going to throw punches, I'm going to be nice and am just going to tap around.' But then it became 'put up or get your a** kicked', every day."
In addition to the sparring, the young actor, who has risen to international prominence with movies such as Percy Jackson & The Olympians: The Lightning Thief (2010), The Perks Of Being A Wallflower (2012) and Noah (2014), had to endure sleep deprivation, along with the others in the cast.
They took turns to do guard duty and, one night, they were ambushed in their beds and tasked to tackle a vigorous assault course repeatedly.
"The whole thing was extreme," Lerman says. "The sleep deprivation was really difficult to manage. We'd get a couple of hours a day and then we were getting up and doing all this physical work as well.
"Also, there was this course that they had us do a couple of times a day and that was really difficult.
"One time they made me do it with a backpack on and it had a lot of weight inside of it. It was tough."
His movie career began taking shape when he was still a schoolboy, with roles in the Mel Gibson films The Patriot and What Women Want (both 2000), as well as the Russell Crowe remake of the classic Western 3:10 To Yuma (2007).
"I started as a child actor. I grew up in LA and it just kind of found me, really, and I just did it," says Lerman, the youngest of three children.
"But it wasn't until a little bit later on in my early teens that I really got my foot in the door.
"Then, when I was graduating high school, it really became clear. There was that choice whether to go to college or to shoot a film. That is when acting became a career choice."
His mother Lisa is his manager and his father is a businessman, according to reports.
Recently, he played the son of Russell Crowe's Biblical hero, Noah, in the epic film from Darren Aronofsky.
"Compared with Fury, Noah was a piece of cake," he says. "Fury is definitely the toughest movie I've ever made."