Strengthen abdominals and thighs by standing with head, shoulders, and buttocks pressed against a wall, feet a foot or so in front, hip-width apart. Bend your knees and slide down the wall a little. Exhaling, contract your abdominal muscles and tilt your pelvis so your lower back presses against the wall. If you canít see your knees when you look down, exhale and descend until you can. Aim to hold, breathing evenly, until the end of the ad break.