The misconception of "lower abdominals" is still alive in gyms, on TV shows and in fitness magazines. Talking about and thinking that there really are muscles known as “the lower abdominals” is prevalent in school Phys Ed classes, personal training sessions and group exercise classes. It’s commonly heard but it’s just not true. There is no such muscle and therefore there is no need to make up exercises to strengthen it. Let it be heard loud and clear! You don’t need to work out, isolate or even strengthen your “lower abdominals” to attain a "flat stomach" or to strengthen your core!
The phrase “lower abdominals” implies that there is an abdominal wall muscle that is lower than the others. This is anatomically false. Just glance at any abdominal chart and you’ll be able to see that each of our abdominal muscles have attachment sites on the pubic bones (right there at the bottom of your jean’s zipper). None of them is any lower than the others.
Some think the words “lower abdominals” merely refers to the lower half of the central abdominal muscle, the rectus abdominus. The problem with thinking the lower portion of a muscle’s fibers are a separate muscle is that this implies the lower half of a muscle can contract without its upper half being affected. This is impossible due to the structural construction of our skeletal muscles. Read on to understand why this isn’t possible.
To understand the abdominal muscles, it is vital to understand the basics of all skeletal muscles. A muscle has at least two ends. These ends attach directly, or by way of a tendon, to at least two separate bones. Each muscle crosses at least one joint. When the muscle contracts, it either causes the joint between the two bones to flex (bend) or causes them to extend (straighten). One end of the muscle, referred to as its origin, is usually stable and doesn't move. The other end, called the insertion, usually moves when the muscle contracts.
Full range-of-motion is recommended
The meaty part of the muscle is made of fibers that stretch from the origin to the insertion. The long fibers in the abdominal muscles go from the origin (on the ribs and xiphoid process) to the insertion site (on the pubic symphysis). A concentric contraction (concentric means “toward the center”), done during curl-ups or sit-ups, is performed as the two ends move closer together. For full range-of-motion to occur on each repetition of the exercise, the muscle relaxes and allows its two ends to move as far apart as possible to regain its resting length. The next contraction happens from this length and is referred to as being done from its full range-of-motion. It’s considered a basic principle of good exercise performance to do all strength building exercises (including those for the abdominals) by going through a full range-of-motion.
The all-or-nothing principle of muscle contraction
The two ends of the rectus abdominis (the main abdominal muscle on the center front of your belly) move toward each other when the muscle fibers contract or one end can hold still while the other end moves toward it. They may switch duties, or they both may move toward the middle. But the entire length of the muscle fiber is always involved no matter which end is mobile. You can not isolate the muscle’s contraction into just one half the length of the muscle.
The “all-or-nothing principle” pertains to the length of a muscle fiber, not to all the fibers of a muscle. One fiber may contract while a nearby fiber does not, but the fiber that is contracting is committed along its entire length. A muscle fiber cannot contract along only half its length.
Imagine a stretched rubber band representing the rectus abdominis. As the rubber band shortens to its resting length, the entire band is involved in the shortening process. This is similar to the way the muscle contracts along its entire length. For one end of the muscle to move, it must be pulled upon from the anchored end at the origin site. Hence, the lower end of the abdominal muscle cannot contract without affecting the rest of the length of fiber.
Spot reducing
Exercisers have been led to believe that exercises for the “lower abdominals” are those that make the bottom end of the abs move or at least feel the pain of exercise (for example: when the hips lift and the ribs remain stationary on the floor). This makes you "feel" the exercise below the waist where most people store most of their abdominal fat. Exercisers gladly try to feel the exertion near this fat storage spot because they believe in spot reducing. They believe that if the pain is near their detested fat pad that fat will be targeted and made to reduce. This dangerous misconception perpetuates the belief that you need to feel pain to gain the effects of exercises.
If “spot reducing” is inherently linked to lower abdominal exercises, then the entire concept is incorrect. Different exercises move either one or both ends of the rectus abdominis, but that movement does not mean the fat above it is being used to fuel the movement. Nor does it mean one particular end of the muscle is going to be strengthened or tightened more than the other. There is no need to switch emphasis of which attachment site is held stationary on any other muscle group to cause directed fat loss. Doing a variety of abdominal exercises is nice and may prevent boredom and fatigue that makes you stop exercising before very many calories have been burned, but the variety is not essential. A full range-of-motion is the best way to strengthen the muscle. A stronger muscle is firmer, harder or tighter. A stronger muscle has a higher metabolic rate and will use more calories daily, even during rest.
It's time to be cognizant and to apply these basic exercise principles to our abdominal wall workouts and stop taking exercise advice from poorly trained “trainers” who pass on erroneous gym talk about "lower abs."
Experts advise us to perform at least four different abdominal exercises to give enough variety to stimulate each of the four pairs of abdominal muscles (none of which are the “lower” abdominals). I'll share my favorite abdominal strengthening exercises in my next article.
Eat right and exercise regularly!
Alice Lockridge