Justin Bieber: Muscle Me Up!

Justin Bieber is looking to add some muscle to his frame with celeb trainer Danny Musico, Life & Style reports.

An insider dished to the mag, “He’s at the prime age to take advantage of what his young physique is capable of.”

Another source added, “He wants to make the transition from teenybopper to full on heartthrob. Just like Nick Lachey and Justin Timberlake did.”

TELL JJJ: Do you think the muscle will be good for Justin?