sábado, 25 de abril de 2015

The Scientific Approach to Abs Training

If we all want hard-looking abdominals, why are they so rare? I'm convincedthe answer is not that people are lazy in the gym, but rather that they don't have the information they need to effectively stimulate their abs...

Mike O'Hearn
For anyone interested in a muscular-looking and fit body, having a nicely structured and well-defined midsection is critical. The abdominal muscles really are special in the way they must be trained; ab training is unique because ab structure is unique. What do you need to know to get awesome abs? Keep reading. Here's a look at training abs from a scientific point of view.

Along for the Ride

You might not like to hear this, but I've got to tell you anyway: If the problem with your abs is that they're covered by a layer of fat, the best ab training in the world won't help at all. You see, everyone has the same basic abdominal muscle structure. (Of course, some people have stronger and more fit abs than others.) Effective ab training will help you strengthen these muscles and provide functional stability to your midsection, but it sure as heck won't bring out your abs. If "hidden abs" is what you're up against, you can crunch until the cows come home. The fat will simply go along for the ride and you'll never see the fruits of your labor.

However, there are two things you can do: (a) begin a good meal plan and reduce your overall bodyfat; and (b) train your abs with intelligence, intensity and efficiency. Now that that's out of the way, let's peel away the fat and take a good look at the abs.

Ab Structure & Genetics

What I'm really referring to (what we see with the naked eye) are the rectus abdominus and the external obliques. The rectus abdominus is the large abdominal muscle in the front of the torso. It is actually one muscle that is divided by four strips of connective tissue called tendinous incriptions.

These strips are believed to be protective devices that keep us from rupturing the entire length of the rectus abdominus. Also, running down the middle of the rectus abdominus, dividing it into right and left halves, is the linea alba.

These divisions determine the genetic shape of your rectus abdominus. I am often asked if you can alter your basic ab shape. I believe the answer is no--not without training anyway. Hey, some people have clear-cut blocks, others have sections that appear a bit staggered. Some have thick, protruding abs, while others are a little more flat. Thank your parents for yours, and make the best of what you've got!

Giving the waist a tapered, sleek look are the external obliques, which have fibers running diagonally down toward your groin. You work this muscle as you rotate inward on a crunch. Again, not much can be done to alter the genetic shape of these muscles.

As Dr. Berl Michel, sports chiropractor in North Palm Beach, FL, puts it, "There's nothing you can do about your abdominal shape. You've got what you've got; it's as simple as that!"

Not to fret; if your abdominal shape isn't quite what you'd like, all is not lost. Remember, few people really make the most of their ab development potential in the first place. There is much to be gained.

Lady doing crunches

Also, you can strengthen, "tone," and slightly hypertrophy (add size to) these muscles. Not only does this aid in lifting and injury prevention, but when you do lose the fat over your abs, you'll expose a finely-toned midsection that is sure to attract attention.

As in most aspects of physique development, whether you've got perfect or not-so-perfect genetic shape, the key to making the most of your potential lies in effective training. Now, there are so many misconceptions about ab training that it's a good idea to define the proper biomechanics and scientific aspects of ab training by what they aren't! Here are some things to avoid:

Common Mistakes in Ab Training

Since you now have a better concept of the abdominal muscles, let's talk about some of the pitfalls you might encounter when working for that washboard stomach. Here are a few things you should know:

Hip Flexor Involvement. Probably the biggest problem you'll face when trying to train the abs is the unwanted involvement of the hip flexors. When activated, these muscles pull the pelvis and spine forward as they attempt to flex the hip; they decrease the angle (perform flexion) at that joint.

The hip flexors, anatomically and collectively termed the iliopsoas, are made up of the psoas major, psoas minor and the iliacus. Also, the rectus femoris, one of our quadriceps muscles, somewhat flexes the hip. (This is why you're a little stronger when you lean back on leg extensions.) These muscles can take over during abdominal training to such an extent that your abs are hardly working at all!

This can happen far too early during an ab exercise in people who have weak abdominal muscles relative to their hip flexors. If their hip flexors take over, they can forget about ab stimulation and fatigue. Sure, they're getting a workout--and they sure as heck feel it--but their hip flexors are doing the work! In other words, if the hip flexors are too strong for the abs, the ab muscles won't get much of a chance to assist when the hip flexors move the trunk toward the legs (essentially what the abs want to do also)!

Making this problem worse is the fact that hip flexor and abdominal movements look like the same thing. So it's important to be able to determine your relative abdominal strength in this position.

Check 'em Out. Here's a quick test you can do to check the strength of your abs compared to your hip flexors: Lie on your back with your legs down and your hands at the sides of your lower back. You'll notice a slight arch in your lower back: you'll probably be able to slide your hands under your lumbar area.

Now bring your legs overhead so that your hip angle is about 90 degrees; keep your knees straight. Here, your lower back will come in contact with the surface you're on and you won't be able to slide your hands under your lower back anymore. In this position, your hip flexors are in a poor position to be forceful and your abs are ready to be contracted.

Tighten your abs and feel your lower back on the surface. Now, very slowly, lower your legs while consciously trying to squeeze your abdominal muscles and keep your lower back down the whole way. With your hands at the sides of your lower back, you'll be able to feel when your lower back begins to arch up. At that point, stop the movement. (On average, most people can get to somewhere around 45 degrees or so.)

This little test can tell us how strong your abs are compared to your hip flexors and can give us a good working knowledge of how much you may be using your hip flexors in abdominal work.
The point where you can no longer keep your lower back down on the surface is where your hip flexors begin to kick in and pull your pelvis forward. In general, the earlier this happens in this movement (relative to the 45-degree midpoint), the weaker your abs are compared to your hip flexors. No matter where you ended up on this test, you should know how to control hip flexor involvement in abdominal training.

Contracted Antagonist. Think of your biceps and triceps, or your hamstrings and quadriceps. As you know, these are antagonistic muscle groups: the actions of one directly oppose the other. By the same token, the abdominals and lower back can be viewed as antagonists as well. After all, in order to contract or shorten one, the other usually must be lengthened.

Now you can see why when the lower back is in an arched position (a shortening of the lower back muscles), whether it's due to hip flexor involvement or any other reason, it's virtually impossible to adequately work the abs. They're forced into a lengthened position. (In fact, abdominal hernias are not all that uncommon when the lower back is violently arched.)

For example, many exercise classes still use low leg raises to "work the abs." In this position, the hip flexors are working hard, the pelvis is tilted forward, the lower back is off the floor, and the abdominals--by and large--are in a lengthened position. You tell me, can the abs contract and be strengthened in this position? The answer is no!

(However, it really is a great workout for the hip flexors!) You "feel" the abs in this exercise because they are doing some isometric work well in hip movement--they work in spinal movement. And, when this spinal movement stops, the abdominal contraction does as well.

The point is this: If you want to train abs, then just train abs, not hip flexors. In order to minimize hip flexor involvement, be careful to only create movement at the spine. When you start moving at the hip--like you do when performing regular sit-ups and leg raises--the abs are no longer primary movers and won't do much work. Read on.

Hip, Knee and Ankle Position. Since the abs are only worked well in spinal flexion, you have to be careful what you do in other areas. In particular, hip, knee, and ankle positions can create problems, when trying to train abs.

As always, keep in mind that you're trying to minimize hip involvement. How can you use joint positions to limit the unwanted use of other muscles? Here's how: If you bend your hips and knees to about a 90-degree angle, you're then better able to train your abs since the hip flexors can't contract with much force here. With you back down, your hips and knees bent, and your head slightly tilted forward, your hip flexors relax and you are in a perfect position to flex the spine.

And what about your ankles? Well, a big mistake here would be to tuck your ankles in under a stabilizing bar. This creates an anchoring effect, and your hip flexors kick in immediately.

This often happens in people who want to increase the relative intensity of their abdominal work. They do what seems right to do--they raise the angle of a slant board.

But to stay on the board they've got to anchor their feet, which brings in the hip flexors early in the movement!

Also, on a standard "sit-up board," the hips and knees are often not bent enough in this position to adequately relax the iliopsoas in the first place. Again, what results can certainly be a good workout, but not for the abs!

The Biomechanics of Ab Training

With all those common ab training mistakes, you're probably wondering how anyone can get an effective ab workout. Well, you know that rectus femoris is just one muscle, and it contracts as one muscle. You also know that the rectus abdominus contracts and shortens during spinal flexion--that is, when the spine rolls forward (chest rolling to hips, or vice versa).

Of course, in order to flex the spine, you've got to round out the lower back (lengthen it). Again, just like in the test above, the abs can only work hard when the lower back is rounded or flattened (against the floor).

Therefore, you should concentrate on keeping the lower back down, slowly rolling it down, and slowly rolling the spine forward from the chest to hips as if you are stacking one vertebra on top of another. No, you can't go very far: the human spine does not flex forward much (unless you're in an extended position to start with). But that's all the rectus abdominus really does!

Here's how you can see the spinal flexion for yourself. Do this, all the while looking at where movement is occurring:

Lie on the floor, contract your abs, flatten out your lower back and do a "crunch," concentrating on stacking one vertebra on top of another. Stop at the top of the movement (not very far).

What you've just done is forward spinal flexion, the only movement that truly trains the abs. You rolled one vertebra on top of the other to get you to the top of a crunch; you flexed your spine. Now, from there, finish a regular sit-up and stop at the top. Where did movement occur to get you there? At the hip. That's hip flexion, and the abs really have nothing to do with it.

So this spinal flexion "crunch" is the only real way to work the abs? Yep, but hold on. That crunch can also be in the form of reverse pelvis tilts, hanging crunches, and so on--as long as the movement is occurring at the spine, nowhere else.

If you find standard crunches are too demanding at first, start with your hands at your sides. You can even do a full "sit-up" and then lower yourself slowly from a crunch position (sort of like an ab "negative").

A great way to increase the relative intensity of your abdominal training would simply be to cross your arms over your chest and hold a small plate in tight to your torso. Remember, abdominal muscles, like other muscles, need change in intensity to stimulate growth now and then. Don't shy away from exercises like kneeling cable crunches, just be sure not to rotate the spine against heavy resistanceÐthat's how you get hurt!

How To Tell What You're Working. Even with this knowledge under your belt, it can still be difficult to tell what you're training during ab work. Nationally-renowned Gainesville, FL, sports physical therapist Steve Forbush, M.S., P.T., gives us this advice: "When doing ab training, if the first point of fatigue is in the lumbar area--around the kidneys--then the iliopsoas is being worked too much." At this point, you should re-evaluate your position and your movement.

Other Ab Training Tips 
  1. Many people like to hold their hands behind their head when doing crunches. Unfortunately, when they begin to strain there is a tendency to yank at the head to get a bit more force. This puts extraordinary stress on the cervical vertebrae, and can be dangerous. If you can't get used to putting your hands across your chest or straight out to the sides, at least keep them near your ears (being careful not to put your head forward), or cross them in front of your chin by grabbing the back of the opposite shoulder!
  2. Never hold your breath during ab training. This increases the rigidity of the spine you are trying to flex! Instead, slowly breathe out through pursed lips on the way up, and inhale slowly on the way down.
  3. I honestly see no good reason to stretch the abdominal muscles. This puts the lower spine in a dangerous position, and the abs get stretched often enough throughout the day.
  4. Most people understand how to activate the external obliques. Remember to slowly and easily rotate during the "crunch" to train these "waist" muscles.
So, by avoiding some of the more common ab training mistakes (like hip flexor involvement), and understanding how the abs work (spinal flexion in short movements), you'll be sure to get the most from your abdominal work, and be well on your way to those impressive looking, firm, washboard abs.

Abs &Lower Back Pain

Well-functioning abdominal muscles are an asset to anyone working hard in the gym. They help support the spine and, when contracted during a light workout, reduce the load on the lower back up to 40 percent! Also, the lower back itself is helpful in resistance training, and lifters need that slight curvature of the lumbar spine during exercises like squats and overhead lifts.
Then why do so many bodybuilders and fitness enthusiasts alike have lower back pain? Although many reasons are possible, a great number of lifters experience this pain because of a strength imbalance between these two antagonists, and/or excessive lordosis. In the latter, the curvature of the lower spine is excessive, and the person appears to have a "sway-back."
If the abdominals are not well-conditioned, the lower spine is subjected to higher-than-normal pressures in an awkward position. This often results in the bulging of intervertebral discs, and the subsequent pressure on nerve roots or a ligament, causing pain. Along the same lines, a strength imbalance between the abdominals and the lower back can lead to a different kind of pain. As in the case of pregnancy or a "pot belly," the abs become stretched, and in many cases are just too weak for the back. An exaggerated arching of the lower back can occur, putting the back at risk of injury and pain. Individuals in this position often wind up in the doctor's office because of a dull, aching pain.

"With people like this," says physical therapist Steve Forbush, "they are in continual lordosis, and their back remains tight all day. They're in pain because their abs are too weak and their back never gets a break!"

Forbush says that often a wrong diagnosis of weak erectors (deep lower back muscles) is made. "Therapists who subscribe to this notion believe that back pain may stem from 'trunk' weakness. More likely, what is happening is that the person develops a weakness after the body inhibits work in that area because it's getting a pain response there."
In short, if you're having lower back pain, see a physician to identify the cause. And, don't be surprised if your doctor recommends abdominal exercises! But remember:

The key to staying out of the doctor's office is to have both a strong abdominal group and a strong lumbar group.
"We're after a good, dynamic ratio between the two. For many, the answer to back pain is in learning. Learning how to contract the abs and lower back at the same time.

This will lead to global trunk mobility, flexibility, and strength," says Forbush.

Lower Ab Training

An area of ab training that causes much confusion is the attempt to train the "lower abs." This often leads to a whole lot of people doing some pretty strange exercises in order to tighten up their lower belly (a concern many women have). Here are a few things to keep in mind:

First, don't forget that the rectus abdominus is just one muscle and it contracts as one muscle, so it'll be tricky trying to get just one part of it to do the work. I will note, however, that it may be possible to put more stress on one section of it (depending on the direction of muscle fibers).

Secondly, the "lower ab section," the part of the rectus abdominus that lies under the naval, poses a few training problems.
  1. The rectus abdominus tapers down a great deal under the naval. In this area, it is a small (compared to the "upper" part), smooth sheath that is not made up of thick, muscular tissue. In other words, there's just not much there to contract.
  2. Since contraction of the abs depends upon forward spinal flexion, we can see another reason why this part of the rectus abdominus is so hard to train. We have no problem flexing the spine in our upper regions, but it is very difficult to flex the spine in the lower abdominal area. This is because: (a) the pelvic girdle is in the way; and (b) the flexible lumbar vertebrae end at about the top of the hip bone, and we're now trying to move the relatively inflexible sacrum. This creates a fight for prime movers status between the hip flexors and the lower abs, one the lower abs tend to lose. "It can be very tough to work the lower abs, since the iliopsoas is so much stronger than the lower abdominals, and they fight for the pelvic tilt," says Forbush.
  3. Women seem to be especially prone to lower abdominal weakness, even if they have never had a child. "After years of monthly swelling in the lower abdominal area, the muscles in this region become flaccid. It's a natural inhibitory response by the body," Forbush explains. Does all this mean that training the lower abs is helpless? No. Since your spine can flex (though only a small amount) when you roll your hips up toward you, it's possible to get the lower ab region to do more work than usual when performing an exercise like reverse crunches (a.k.a. reverse curl)--as if you are curling your buttocks up toward your torso. This can be done while hanging as well as lying on your back (with your legs well above you).
    "I really believe that the lower abs work a bit differently than the upper abs. And, the umbilicus seems to be the dividing line. With the legs out of the picture, and by bringing the pubic bone to the umbilicus, you're better able to activate the lower abs," Forbush claims.

AB-Solutely Bogus

Ready to forget about the crunches and go for the "ab machine" you see on late-night cable? It sure sounds good on the infomercial, doesn't it? Hold on! William Whiting, professor at the University of California, Northridge, found no overall physiological advantage to these machines--such as the AB Roller Plus, the ABSculptor, and AbWorks. Whiting measured the electrical activity of three abdominal muscle groups, with and without the ab contraptions. The muscles weren't any more active with the machines.

Point is, if you want great abs, you should adopt a smart diet, and use a spinal flexion movement with variety in consistent workouts. And stay away from the hype of hucksters! 

From: MD 

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