Ryan Phillippe insists the bootcamp he and his Stop-Loss co-stars took before filming started was the most gruelling in movie history.

The actor and his castmates were put through extensive military training so they could get into shape and into the minds of the U.S. troops they portray in the film.

And Phillippe is sure his Army training was more intense than that other actors have been put through prior to war films in the past.

He says, "I’d never been through a boot camp as extensive as this one. We would do 14 hours a day in a six day week. It was 106 degree temperature in the middle of nowhere in Texas.

"From a distance you would not have thought it was actors preparing for a movie. They put us through a relatively hardcore training but I loved it."