How to do it: Loop a resistance band around your ankles and lie on your right side, supporting your upper body with your right hand and forearm. Extend both legs out, feet flexed. Brace your abs in tight and lift your top leg up to hip height, rotating your leg to turn your toes down to the floor, keeping tension on the band. Lift your leg slightly higher than hip height, pushing against band, with heel rotated up to the ceiling. Return to hip height. Repeat 20 times quickly and then switch sides.