The Benefits – To develop the upper and lower abdominals.  Leg tucks enables you to crunch rib cage and pelvis together instead crunching either one towards other, which let you work more muscles in a less time.

Execution - it cross on a bench and take a hold of the sides for support. Keep your knees slightly bent and lean backward at about 45 angle. Feel the crunch movement by bringing your upper body towards your pelvis and simultaneously bring your knees towards your head. Now straighten yourself back to the starting position.

Tips - Feel the crunch as you squeeze rib cage and pelvis together. Do not rush with this movement. Perform each rep under full control. Seated leg scissors allows you to perform the exercise more comfortably than leg scissors on the floor.