Justin Bieber says he’s a changed man – and he wants to be a “class act”.

The 21-year-old singer – who had a rocky 2014 – showed off his physique on the cover of Men’s Health magazine.

And he told the April issue: “I do aspire to be a class act.

“This has really been a big year for me, as far as figuring stuff out.”

The star, who pleaded guilty to careless driving and resisting arrest charges last year, said: “This is almost like a full 180 from how I was. Yesterday – a year from yesterday – I was in jail,” E! News reported him as saying.

Justin Bieber
Justin Bieber (Abaca)

The singer added: “I had to grow up so quick. And it was almost like I grew up for the public but I didn’t necessarily grow up. There were things I had to do, as far as the way I had to make relationships, and conversation, but as far as actually growing up, there were a lot of things I missed out on.”

Justin, who previously posed shirtless for a Calvin Klein advert, also denied that he was “self-centred”, saying that he was “very much a relationship guy”.