The Forgetting Sarah Marshall star admits he has adopted the unusual exercise regime, which involves clambering over buildings and running through strange spaces, to keep fit, but insists he does not invade private gardens or homes.

He tells, "It's basically trespassing, not going in people's personal properties but urban climbing, free running in straight lines. All that business. But it's not instead of sex, I don't ejaculate when I'm doing it, it's just a reclamation of my personal freedom."