One Direction are so dedicated to their work out regime that they splashed out £10,000 on flying their personal trainer out to New York on a private jet.

The ‘Best Song Ever’ stars are quite attached to their trainer Mark Jarvis and brought him out even though they had trainers at their hotel in New York City.

Speaking to the Daily Star, Jarvis’ agent Ramzy Khachnik said: “They said to Mark: ‘We need you, please fly out, come as soon as possible.’

“They wanted him to get on the next plane, so they laid on a jet for him. It’s incredible how much they want to build up their bodies.

“They haven’t trained for the last couple of weeks and are feeling edgy and uncomfortable.

“The One Direction film is going to be a box-office hit and they didn’t mind splashing out to get him there.

“The lads have told Mark he’s crucial to their future.”

Watch the lads working out for the Brits last year below: