If you are looking to get a great set of abs, then you need to do your abdominal exercises correctly.

Certain ab exercises are more effective than others, so if you are short of time, focus on the best abdominal exercises first.

If you are thinking the traditional crunch is the best, then think again. In a recent study of 13 common abdominal exercises and their effectiveness, the traditional crunch came in at the bottom three.

So which ones made the top? The bicycle crunch, captain's chair and exercise ball crunch came in at the top.

The bicycle crunch was rated the number one most effective ab exercise for the rectus abdominal muscle (or your six pack muscles).  It came in second for effectiveness on the oblique muscles and was rated number one overall.

How to Do the Bicycle Crunch

1. Lay down on the floor on your back.
2. Lift your right leg (bending at the knee).
3. Place your hands loosely behind your head.
4. Lift your upper body, twisting at the waist.
5. Bring your left elbow to your right knee.
6. Switch sides and switch legs by twisting the other way and bring your right elbow to your left knee.
7. Repeat this several times.

Check out the video below to make sure you are doing it correctly.

Although the traditional crunch was third from the bottom of the study, it was still effective. In fact, all the exercises studied showed some effectiveness to the abdominal muscles. The traditional crunch is a great ab exercise especially if you are just starting out. This exercise is less stressful to your lower back and can help tighten and tone your rectus abdominal muscles for a great six pace.

How to do the Traditional Crunch

1. Lying down on your back making sure your back is flat to the floor.
   
2. Place your hands loosely behind your head.
3. Bend both knees and place your feet flat on the floor.
4. Now lift up using your ab muscles (not your hands) and contract the muscles.
5. Repeat this several time.

You don't need to come up off the ground very high to be effective. In fact this exercise has a very small range of motion.