Justin Bieber has been hitting the gym!
The 23-year-old singer took to Instagram on Saturday to show off his late-night activities: shirtless arm wrestling!
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The Biebs also gave fans a close up of his game face with a few silly selfies.
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On Friday, Beiber debuted a new tattoo, reflecting on his past mistakes and explaining that he wants to "work everyday to be BETTER AT 70."
See more in the video below.