Six Pack Abs ?

Most people just want a flat stomach. Some more advanced want what is called a six pack( or the definition that separates the abdominal muscles.) Both are achieved the same way and it isn't sit ups. The first thing is diet. You need to burn more than you eat. This is usually the biggest problem. All the common sense choices apply . Avoid desserts, stick to lean protein, avoid starch (rice, bread, pasta and even corn), and eat several small meals not one big and two small.
The second is more cardio. If you don't do any walking or stationary machines...start. You need to get you heart rate up for 30 mins. at a time and you need to do this several times a week. This will not only help you burn more calories but it will also rev up your metabolism.
The third is crunches not sit ups. Sit ups work the hip flexors more than the abs. Crunches are done with less range of motion and more concentration. Lay on your back with your knees bent. Reach over you knees until your shoulder blades come off the ground. You should feel this in the upper stomach not the back. When you have this down, try the same thing with your feet up in an L position. This works the lower abs more than the upper.