'Climax' sensation Usher has celebrated the beginning of 2013 with a few trips to the gym to get himself in fighting shape for his upcoming new movie role.

The R&B superstar is set to star in a boxing biopic entitled 'Hands Of Stone', which he confirmed his involvement in last year, and he will play a character named Sugar Ray Leonard. The film documents the life of Roberto Duran and also features legendary actor, Robert DeNiro.

Usher posted a series of photographs to his official Twitter page via Instagram (shown below and left) earlier this week that show him working out, and he accompanied the images with the captions:

"1st day back in the gym...Man!! 2013. Shout to Biggs...I'm back and focused. Let's get it!"

The sexy star has also joined The Voice USA for Season 4 and during a recent interview, he explained the appeal of becoming a coach on the programme: "I knew that - they made it look so easy and fun. That's the thing that attracted me. The credibility of the show speaks for itself. It's not about tearing people down, it's more about building people up."