Crunches can also be done on an exercise ball and many feel it is more effective than standard crunches. You sit on the ball and place your feet on the floor about a foot apart. Roll back carefully on the ball until you are lying with your back firmly against the padding. You should have the Roman Chair set high enough that your legs dangle straight down when you are in position. Then slowly bring your knees toward your chest as far as you can go and hold for a few seconds before extending them to the beginning position. This exercise was number two in a San Diego State University survey that ranked the top abdominal exercises and equipment. This type of home fitness equipment, it is important to fully research the equipment and give it a test ride. Most companies charge shipping and handling to return online orders if you return an item for reasons other than manufacturer defects or damage. Gravity resistance If you are looking for something a bit more high-tech, there are several pieces of equipment made