The following video demonstrates the increase in strength through a crunch movement when the abdominal group has been activated. The crunch movement is a basic ab exercise that uses majority of the abdominal group muscle to perform the movement. The before test indicated that the muscles in the neck were over used and dominating the movement. After activations the test indicated that the muscles in the neck had stopped being the primary driver of the movement and the abdominal group had a greater roll in the movement creating more strength in the second test. Read through " How to improve abdominal strength without doing ab exercises.