Harry Styles is apparently following a military fitness plan on the advice of Clint Eastwood.
The One Direction star was talking to Clint about a career in Hollywood and the legendary filmmaker gave him tips on getting into shape for potential action roles, reported the Daily Star.
Harry then signed up for Krav Maga, a self-defence system developed by the Israeli armed forces which involves wrestling, boxing, street-fighting and martial arts.
A source said of Clint and Harry's chat: "They discussed movie projects and then got on to the subject of achieving an action hero's physique.
"Clint had plenty to say on what Harry should do if he ever wanted to be considered leading man material."
Harry, 20, has also got his bandmates Liam Payne and Louis Tomlinson to try the tough work-out.
The insider said: "Louis and Liam are also raving about KM now. They've even been having a body competition - comparing their biceps over Instagram!"
Clint isn't the only Tinseltown legend who apparently thinks Harry has a shot at a silver screen career, as last week it emerged that film boss Harvey Weinstein offered the curly-haired singer a part in his new movie Tulip Fever.
Harry had to turn it down because he was too tied up performing with his bandmates, but movie mogul Harvey still has his eye on the singer. "He's like Errol Flynn, he's got that swashbuckling charm," he said. "Definite star potential."