The celebrity trainer behind Barry's Bootcamp, Joey Gonzalez, counts some of the biggest names in show business among its clients: Jessica Biel, Jake Gyllenhaal and Katie Holmes, to name a few. READ: Get a Better Butt In Just 15 Minutes a Week But perhaps no celebrity in Hollywood has a larger — ahem — asset than Kim Kardashian. We asked Gonzalez, a CEO and partner at the renowned gym, to demonstrated three of his favorite exercises for a perfect posterior like Kim's. Watch the video above to see how he does it, and get started on your way to a better backside. Need inspiration? Check out some photos of Kardashian below.