Justin Bieber has been working out to ''get sexy for the ladies''.

The 18-year-old singer - who recently admitted he doesn't know what is going on in his on/off relationship with Selena Gomez - has been hitting the gym more than usual lately and Justin admitted he wants to bulk up to impress the opposite sex.

He told Macleans.ca: ''I've been working out in the gym, getting bigger, trying to get sexy for the ladies.''

Justin also said Michael Jackson is his inspiration and he hopes to become as successful as the late King of Pop.

He said: ''I model my career on the decisions Michael made and how he kept his young fan base and kept his private life private. All those things add up to me. That made him super interesting.''

Justin's manager Scooter Braun revealed despite the 'Beauty And A Beat' hitmaker's massive wealth, his prized possession is a signed picture of Michael.

He explained: ''Justin is not attached to material things at all. He has a signed picture of Michael Jackson and that's the only thing he cares about losing.''