It's booty sculptin' time! Prepare for lift off: these three must-try butt exercises are Anna Kaiser's favorite. We chatted with the celebrity trainer, who has been prepping Shakira for her world tour, and asked what her all-time best moves were for toning and sculpting the derriÃ¨re. She delivered some seriously awesome answers. Do these three during your next session - and you might have trouble walking for a few days!