There are many layers of muscles involved with “good abs.” One layer can be generalized as the “broad muscles,” which wrap around the trunk in 3 different layers; the “rectus abdominis,” that stretches down the front of your belly; and many internal muscles that are less obvious but still participate in the function of the abdominals.
The job of the abdominal muscles is twofold: 1) to contract or stretch to move the skeleton of the trunk – the ribs, spine and pelvic girdle – in different directions and 2) to encase the viscera (your guts) of the belly. To work these muscles, we often take a “skeletal” approach (there’s a noticeable action involved with crunches or leg raises), but we should never forget the “visceral” aspect of this core group of muscles.
Closing at a “zipper” (of non-contractile tissue) at the front of your belly are the 3 layers of broad muscles: in the deepest layer the fibers run horizontally around the viscera, the most superficial layer runs diagonally like a “V” (from the back of the ribs to the front of the pelvis) and the middle layer runs diagonally like an “A” (from the sternum to the iliac crests). Their combined function allows your trunk to move in a wide variety of ways.
Another layer makes up the recognizable “six pack” pattern of the front of the abs – these fibers run straight up and down, from sternum to pelvis, and are divided by horizontal sections of “non-contractile” tissues – this causes the muscles to build up thicker in sections, creating the “six pack” look we see on healthy, fit individuals. These can be called the “rectus abdominis.”
One of the less obvious sets of muscles (but very important to remember) are those of the perineum or the pelvic floor: these hold the viscera (your guts) up against gravity. Certain exercises aimed at working the front abs can put pressure on the pelvic floor, stretching those muscles but neglecting to make them stronger. This can lead to imbalances in their function later on (as do other conditions such as excessive weight, age/gravity and, of course, childbirth). Therefore it is important that, when you engage and work out the muscles of the abs, you also engage and work out these often forgotten pelvic floor muscles.
To achieve a flat belly, try incorporating these methods:
1) Alternately contract and stretch the muscle fibers. This movement promotes blood circulation to the belly of the fibers, nourishing the tissues and promoting “sweeping” of the acids of the muscle. In a true contraction (i.e. pulling your sternum closer to your pelvic bone), the contractile fibers of the muscle shorten and thicken while the non-contractile muscles are put under tension. In a stretch, both contractile and non-contractile tissues are put under tension.
2) Alternately contract the broad muscles: think of the broad muscles as a three layer latticework, adhered to each other. When one layer contracts, it draws the other two layers of muscle along with it in the direction of its contraction. If the next contraction focuses on fibers running in another direction, the same action occurs and all three layers move in that new direction. This practice involves all three layers and promotes the sweeping/massage action to nourish and cleanse the tissues.
3) Alternately contract and stretch the broad muscles and the rectus abdominis: doing so massages the non-contractile fibers that “zip” up the broad muscles. This will promote mobility and elimination of the muscles being stretched.
4) Mobilize your ribs. Then, coordinate your breath with the movement. Try to incorporate costal breathing; keep the ribs open through the exercise to incorporate the diaphragm and help you relieve some of the downward pressure on the perineum.
5) Coordinate the abs with the perineum – one way is to contract the perineum when working the abs in “skeletal” mode (moving them to move the skeleton in different ways), another is to give the area a “wake up call” by doing a few perineum exercises before each session of abs work.
6) Consider practicing an “ascending contraction” when contracting the rectus abdominis: first engage the pelvic floor, then the lower abs and work your way up.
Everything takes time and effort. As long as you don’t expect any overnight miracles, a little effort every day in the direction of your goal can accomplish amazing things.
Namaste.
Recommended reading: No-Risk Abs by Blandine Calais-Germain and Anatomy of Breathing by Blandine Calais-Germain
Erika Diane 