How do I perform an arms overhead floor crunch?

Lie on your back with your knees bent, feet placed flat on the floor, shoulder-width apart. Extend your arms overhead, keeping your upper arms by your ears. Draw-in your navel and tuck in your chin. Crunch your upper body forward, keeping your arms by your ears. Return to the starting position and repeat.

Lie on your back with your knees bent and feet flat on the floor. Toes are pointing ahead and feet are approximately shoulder-width apart. Arms are by your ears, extended overhead. Draw your abs in by pulling the area just below your belly button toward your spine. Exhale and slowly crunch up lifting the upper body, thinking of bringing your lower ribs toward your hips and keeping your arms extended by your ears. Hold the crunch position then slowly lower your upper body back to the floor, keeping your abs drawn in. Repeat for the required number of repetitions.