This Shirtless R&B Singer Is Hitting the Gym — Hard: Guess the Ab-tastic Star! (PHOTOS)

Usher posted that photo on January 7, writing, “1st day back in the gym...Man!! 2013”

By “1st day back,” we assume he means he’s only been away for a day or two. Because that’s not a lazy person’s physique.

If it were, we’d also have a six-pack.

Click through for more photos of stars at the gym!