Purpose: To tone and tighten the midsection, especially the lower abs.
Execution: Anchor yourself on the bench. Keeping your lower back flat on the support, bring your legs up as high as possible, contracting your lower abs, with a slight bend in your knees. Curl your hips off of the bench as you lift your legs and squeeze and hold at the top of each rep for a quick second. Be sure to exhale as you raise your legs at the top. Lower your legs slowly and under control, allowing your hips uncurl back onto the support before completing another rep.
To increase the difficulty of this exercise you can straighten your legs. Be sure to still maintain a slight bend in your knees as you bring them up as demonstrated in the image below.