2. Low-Belly Leg Reach Looking to targets those corset and six-pack muscles? Start by lying face up with your hands behind your head, knees bent to 90 degrees, and abs contracted. While keeping the knees stacked over your hips, lift the shoulders and crunch up; inhale and hold for three to five seconds. Exhale and extend legs to a 45-degree angle; hold for three to five seconds while squeezing lower belly. Aim for two sets of 10-15 repetitions.