Katy Perry has released the music video for her new single, "Part Of Me," and the pop star ditches her cleavage-baring couture dresses and rocks out in full army attire!

Russell Brand's ex-wife recently told MTV that she worked overtime with boot-camp instructors and real Marines to make the vid, "practicing fireman carries and munching on MREs and getting in touch with her inner bad*ss." Check it out above!