Lie face up flat on the ground with the feet flat on the floor and the knees bent up in the air. Place a kettlebell on the ground over the head, reach overhead with both hands, and grip the kettlebell by the handles. While keeping the arms straight, pull the kettlebell over the head to directly above the chest. Hold the kettlebell over the chest and draw the belly button in towards the ground to help pull the rib cage towards the hips, lifting the back off the ground to perform a crunch. Lower slowly back to the floor, and once the back is flat on the ground lower the kettlebell back overhead.