2AM‘s fitness fanatic Changmin revealed a picture of his ripped back muscles. On March 12, he tweeted a picture with the caption “A man’s back. Let’s lose a little more weight for the upcoming comeback.” (Lose weight? Is he kidding?)

The picture showcases Changmin’s defined back muscles as he pulls himself up at the gym. (Look at those wings!) His shoulder muscles are wide and very prominent as well, showing off his narrow waist.

Some Netizens who saw the picture said, “My jaw just dropped open. This is not a joke!,” “How much did you work out to get that? Impressive,” “Your muscles are breathing and living,” and “Your body is really defined.”

Changmin is working out hard for 2AM’s comeback, which will be on March 13 at 8:00PM via Youtube. Make sure you check it out!