Vertical Leg Crunch:

Lay down on a mat with your legs straight up in the air perpendicular to the floor with your arms besides your body and hands on the floor for support and knees crossed. Inhale in this position.
Raise your shoulder blades off the floor and bring your head towards your legs, and exhale at the top. The movement is small, only several inches. Suck in your stomach in while you do the exercise by imagining bringing your belly button to your spine.