ABSculpting 101, Part 1

Rectus Abdominis Function & Exercises
The muscle that extends from the top of the pelvis to the sternum is called the rectus abdominis. This is the primary abdominal muscle, which when properly developed (assuming that the person has low enough body fat levels), will give the illusion of a six-pack. Its function is to pull the upper torso towards the hips when the body is only slightly flexed at the waist. This is the reason why if you are doing a sit-up, any additional torso movement done past the initial 30 degrees from the floor will not stimulate the abs; instead the hips will be the ones that will complete the movement. Because of this, partial sit-ups performed with the torso moving up to 30 degrees and crunches are great allies in our quest to achieve great abs.

However, if you really want to maximally stimulate the abdominals, prevent lower back problems and get the most "bang for your buck" so to speak, then you need to also consider the fact that the anatomy of the rectus abdominis is such that if you do not bend your torso backwards by around 15 to 20 degrees then you won't be able to accomplish these things. Since the floor only provides a flat surface, not only your abs will not get maximal stimulation, but also they will not learn how to properly contract and protect your back when your body is bent backwards (as is often the case when advanced bodybuilders perform exercises like standing military presses).

The only way to get around this is by investing on a swiss ball (also known as exercise ball). A swiss ball is a great small investment (they run for about $30-$45) as this apparatus will allow you to get the necessary backwards bend that your torso needs in order to maximally stimulate your abs.

So because of this, crunches performed on an exercise ball are the way in which we recommend you perform this exercise.

Since the rectus abdominis also has muscles in the lower region that help maintain proper postural alignment, it becomes necessary to include reverse crunches performed on the swiss ball (make sure that you hold to a stationary sturdy object) as this exercise will allow you to go below the neutral (flat) position.

Another good lower abdominal exercise is the hanging leg raises. The key for maximal stimulation in this exercise is to roll the pelvis slightly backwards at the beginning of the movement.

Oblique Muscles Function & Exercises
The external obliques are the muscles at the sides of the waist. The external oblique complex actually consists of three layers of muscles: the internal obliques, the transverse obliques and external obliques. Together, these muscles contract to tilt the torso, as well as twist it, from side to side. While a bodybuilder would not want massive obliques as this would take away from symmetry and give the illusion of a thick waist, these muscle do need to be trained in order to maintain ideal postural alignment.

A great exercise for these muscles is the side bends performed on a swiss ball. Another exercise that also needs to be performed for these muscles in order to exercise its rotating capabilities are the Russian Twists.

The Intercostal Muscles
The intercostals are the muscles of breathing that lie between the ribs and show as bands of muscle angling downward in the sides of the rib cage and the upper abdomen. The intercostals come into play by flexing the torso and causing it to twist, so doing any type of twisting crunch on a swiss ball will stimulate this group maximally.

The Serratus Muscles
The serratus anterior muscles are the finger-like strands of muscle on the rib cage between the front abs and the lats. Their job is to depress the rib cage and also assist in bringing the upper arms from a position pointing directly up from the shoulders to one pointing directly below the shoulders. A good exercise that will stimulate these muscles is the one-arm cable crunches (using an overhead pulley).