Best Abdominal Exercises
Basic Crunches: The cornerstone of most workout programs, the basic crunch requires no equipment and a little knowledge of exercise form. The ab rocker helps stabilize and guide your crunch motions, and the basic crunch is the same movement without guidance from any equipment. If done properly, then there shouldn't be any neck or back discomfort.
Place your hands behind your head or on the sides of your head, but be careful to not pull up your head and neck with your hands; use your ab muscles and slowly bring your elbows a little less than halfway to your knees.
Bicycle Kicks: Once you've mastered basic crunches and are able to complete at least three sets of 15-20 crunches each, try bicycle kicks, which work out all of your abdominal muscles. Lying down in the standard crunch position, lift your legs in the air slightly and keep your knees bent as if you were riding a bicycle. As you begin to bring one elbow up, bring the opposite knee up as well.
You'll bring your elbow up as the opposite knee comes up to meet it. As you complete that motion, straighten out the knee and bring the other elbow up to meet the other knee. After some practice, you'll be pedaling in the air, alternating elbows and knees.