Justin Bieber gets back to the gym for Calvin Klein job

Justin Bieber has been back at the gym this weekend, delighting Instagram fans in the process. The 21 year old Canadian, currently reigning supreme in the UK singles chart, is spending January - at least in part - just like the rest of us, by getting back to the gym.

A photo posted by Justin Bieber (@justinbieber) on

He'll need to stay in shape to keep up the demands of his role as the face of Calvin Klein underwear. His personal trainer Patrick Nilsson told, "He has put on 20 pounds of muscle and he’s still working on it. It’s a work in progress. We want to put on at least 15 pounds, he’s going to get even bigger, that’s the plan."
back in the gym, A photo posted by Justin Bieber (@justinbieber) on
Bieber is enjoying the spoils of his musical renaissance, with three singles in the Top 10 of the British charts this week. His laid back ballad Love Yourself took the No.1 spot in Friday's chart, while Sorry is No.3 and What Do You Mean? is at No.4. His album Purpose is in the charts at No.4. And after all that, it's no wonder he appears to be worn out...
Sweet dreams A photo posted by Justin Bieber (@justinbieber) on
More stories Bieber strips off for an ice-cold dip in new video Bieber tells Ellen what he thinks of nude photos