8. Plank/Pelvis Tuck Looking to tone your rectus abdominus (aka six-pack) and transverse abdominus (aka waist-cinching corset muscles)? These tucks will do the trick. Begin by lying face down with your legs extended, your elbows bent, and feet at a hip-width apart distance. Then contract your abs, and tuck your toes to lift your body, with your elbows directly under your shoulders. Hold for four breaths. Bend knees (do not touch ground), tilt pelvis up; hold for four breaths. Keep the abs tight, straighten the legs, hold for four breaths. Repeat three times.