Abdominals 101

This month I went to the bookstore to purchase my usual supply of fitness periodicals, and judging form the lead articles on the cover, you would think that the only way that you could tell whether or not someone was in good physical condition would be to ask them to remove their shirt so you could take a look at their midsection! “Unbelievable Abs! The Workout”, “Killer Abs; Our Crunch Exclusive” and “Dynamite Abs; The Ultimate 15-Minute Workout” are just a few of the headliners available at your local newsstand. Why are well defined abdominals the ‘hallmark’ of fitness? Can we effectively target that part of the body? What are ‘washboard abdominals’ and can(or even should) the average individual achieve them?

To understand the musculature of the abdominal wall, it would probably be helpful to review ‘Anatomy 101’. The drawing on page two illustrates a cross section of the abdominals. You will notice that there are two long bands of muscle attached to the fourth and fifth ribs which run all the way down to the pubic crest. This is the most superficial of the abdominal muscles known as the rectus abdominus. When an individual possesses a(sometimes dangerously) low body fat to lean body mass ratio, this muscle appears to be separated into four divisions. These ‘washboard abs’ are caused by thin bands of muscle tendon known as tendinous inscriptions.

The apparent divisions of the rectus abdominus by the tendinous inscriptions have given rise to the incorrect notion that there is such a thing as upper and lower abs. Entire abdominal routines have evolved around the notion that you can actually work one portion of the rectus abdominus in isolation. The best way to illustrate the actual functionality of the rectus abdominus is to picture yourself holding a large rubber band with one end in each hand. The rubberband represents the long muscle of the rectus abdominus. If you stretch the band from one end, is there any less tension at the other end? No, there isn’t, because it is one long band, not four individual bands. Although different motions will produce a sense of muscle fatigue in different portions of the muscle, it is very difficult, if not impossible in some cases, to isolate one small section of any muscle.

In addition to the rectus abdominus, the abdominal wall is comprised of the transversus abdominus, and the internal and external obliques. Of these muscle groups, the transversus abdominus is the most difficult target and strengthen. It is difficult to see the transversus abdominus in the illustration because it is the deepest layer of the abdominal muscles, but it actually wraps around the entire abdominal wall. It aids in childbirth, forced expiration(exhaling) and it holds in the abdominal contents(your internal organs). Remembering that the only effective way to strengthen a muscle is to shorten the distance between the muscle’s point of origin and point of insertion, you will understand that it is virtually impossible to design an exercise that will accomplish that goal in this instance. However, if you remember the barking commands of an army drill sergeant to “suck it in”, you’ll have the best chance of isolating the muscle. A good way to rehabilitate this muscle after childbirth or an invasive surgical procedure is to kneel on you hands and knees and just “suck it in” and hold until the muscle is fatigued. This is known as ‘prone stabilization’.

The internal and external obliques are often grouped together since they are virtually the same type of muscle, with one group in the front and one group in the back. The internal obliques insert at an angle which is often referred to as the same angle that your hands would go into your front pants pockets. The external then would be at an angle of ‘reverse pockets”. These muscles working by themselves help to rotate the trunk, while working together together flex the trunk on the pelvis. One of the interesting functions of the obliques is also the same as the tranversus abdominus in forced expiration. Remember the expression, “I laughed so hard that my sides ached”? That’s because your obliques become fatigued from laughing or hiccoughing. To effectively strengthen the internal and external obliques trunk flexion with a slight rotation at the angle of insertion would be most effective

So how many crunches and how often should they be done to get those highly touted washboard abs? Truthfully, most of us will never achieve that ’hallmark of fitness’. Those ripples are more a sign of a dangerously low bodyfat to lean body mass ratio, than of being in good shape. You must also remember that muscle strength and muscle hypertrophy are not equivalent. In other words, you could do three hundred sit-ups(because you have developed muscular abdominal endurance through repetition), but your muscles may not have gotten any larger . A good prescription to follow in your abdominal routine is to work your muscles like you would any other muscle group; to fatigue. This should take no longer than 10-15 minutes. Finally, remember to give your muscles that 48 hour rest-and-recovery period so that they actually can get stronger. Your ‘abs’ will thank you for it!