Doing any sort of movement with a resistance band will engage your core to keep you from succumbing to the band's pull. For this move, hook a thin band around an anchor point and step away from it to create tension in the band. Hold the band in both hands at chest level. Press your hands away from your chest in a straight line, resisting the rotational forces trying to pull you toward the anchor. Slowly draw the ABCs in the air with your hands, making sure to only move your arms and not give in to the resistance band. Once make your way to Z, flip directions and hit the other side.