Abdominal muscles can be strengthened through such exercises as crunches and trunk flexions, not through the usual sit-ups and leg lifts. Good abdominal muscles can mean greater diving ability, the primary reason why divers should strengthen their abdominal muscles.
Divers need good abdominal muscles, but why? Another question is how? Two exercises popularly thought to benefit abs – situps and leg lifts – don’t work them as well as other exercises. Why not? What can you do instead? Why do strong abs help your back? What exercises flatten your abdomen?
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Why Improve Your Abs?
Abdominal muscles have a busy schedule. When they’re in good shape they are one of the muscle groups that keep your hip, leg and back bones at healthy angles to avoid early wear and tear. Good abs help you breathe during hard exercise, partially protect your internal organs, assist childbirth and prevent certain types of low back pain. During diving you use your abs to lift tanks and gear, walk wearing tanks, rescue a buddy, shout over distances and stabilize your trunk during hard finning. A little improvement to your abs can boost your diving and overall quality of living.
How Muscles Work
To understand how to improve your abdominal muscles there are important things to know about muscles in general. All muscles originate on a bone, cross a joint, then insert onto another bone on the other side of the joint. When a muscle contracts, it pulls on the bones to move the joint it crosses. Muscles can only contract and pull. They cannot actively lengthen to push the bone away. Another muscle on the opposite side of the bone contracts to pull the joint the other way. The muscle in front of your upper arm (bicep), for instance, contracts to pull your lower arm to your upper arm. To straighten your elbow, muscles in back of your arm (triceps) contract.
How Your Abs Work
Your abdominal muscles connect your ribs to your pelvic bones. When your abs contract they pull your ribs closer to your hips by bending your vertebrae. By contrast, situps and leg lifts move your trunk and legs closer, principally using muscles that connect your trunk to your legs. Your abdominal muscles do not connect to your leg bones. Torso curls called crunches bring your ribs closer to the hips, isolating your abs. More on this later.
Your abs were named for their layout in your body. The ab that runs straight down your front is the rectus abdominis, which is Latin for the straight abdominal muscle. Your rectus abdominis starts where your ribs come together in the middle and runs straight down to the front of your pelvic bone.
The abs that run diagonally across your trunk are your oblique abdominals. The obliques are interesting muscles. The outer set, called external obliques, originate at your sides and run diagonally down to your pelvic bone. If you put your fingertips in your pants pockets, your hands line up in the direction of the external oblique muscle fibers. When the external oblique fibers on the right side of your body contract they pull your right side closer to the middle of your pelvic bone. In other words, you twist to the left. When you contract your left external oblique, you twist to the right. Contract both to bend forward.
Your internal obliques lie under your external obliques in the opposite direction. If you cross your arms over your abdomen your fingers assume the direction of the internal fibers. Your right internal oblique contracts to pull the middle of your ribs to the outside of your right hip, twisting you to the right. The left internal oblique twists you to the left in similar fashion. Yet another ab muscle, the transversus, helps compress the abdomen.
Why Do Good Abs Help Your Back?
Of several theories relating abdominal muscles to back health, some are debated hotly. The following two are well substantiated.
Your rectus abdominis is like a support strut in the front. The obliques stabilize from the sides. Together they maintain slight tension all the time to prevent you from swaying backward while standing and sitting. People with weak abs can’t maintain their posture. As a result, their vertebrae do not stay seated in healthy positions. Years of rubbing and straining at bad angles contributes to early wear and back pain.
Your obliques also attach into a fibrous sheath that connects to your back muscles. Strong obliques pull these back muscles to each side like a dynamic corset. By reinforcing the support structure for your back, good obliques reduce the load and strain on your back muscles.
Why Not Situps And Leg Lifts?
In the classic situp you raise your trunk toward your leg by bending at the hip. Leg raises lift your legs closer to your trunk, also by bending at the hip. Bending the hip is called hip flexion. The muscles you feel working during situps or leg lifts are your hip flexors. They lie deeper than your abdominals. The hip flexors start on your lower back bones, cross your hips and attach to the top of your leg bones. The abdominal muscles do not cross the hip and so are not used in hip flexion. If they were, you could work out your abdominals by the most frequent form of dynamic hip flexion – walking.
The three major hip flexors are the iliacus, psoas (which rhymes with “Moe is,” with a silent p) and rectus femoris. The iliacus and psoas, often lumped together as the iliopsoas, are the filet mignon muscles. Beef animals are prevented from exercising their hip flexors to make the muscle soft and fatty for humans to eat.
Although the abs also contract during situps and leg lifts, they do not exercise over their range. They contract mainly at one length, a contraction called isometric. The word root “iso” means “same” and “metric” means “length.” There are better exercises for your abs without the risk situps and leg lifts pose to your back. Unless you need extraordinary hip flexor strength for rugby, ballet or gymnastics and are willing to take extra care to avoid back strain, stick with curls for ab work.
How Can Ab Work Hurt Your Back?
Substituting situps and leg lifts for ab work can injure your back over time. Other popular ways to add to back pain and strain are neglecting your back muscles and overdoing ab work.
Situps and leg lifts contribute to back pain in two ways. All three hip flexor muscles attach to your lower spine. The spine was not built to withstand the strain of constant sit ups and leg lifts.
Another problem with these two exercises occurs when they shorten the hip flexors. Short, tight hip flexors pull the pelvis forward. The shift in the normal tilt is one of several contributors to low back pain. Too tight hip flexors are common in people who sit a lot and who overdo hip flexor exercise without stretching their hip flexors. Strong abs balance the pull.
Abs create an important support structure for your lower torso but they are not the entire support. Many people mistakenly confine themselves to abdominal exercises alone, thinking it will make their backs injury free. There are two problems with this. Without adding exercises that actively contract your back muscles, you could reach a point where your weaker back muscles can’t counter the chronic muscle tension from your abs. The resulting forward slouch slowly puts unhealthy pressure on the joints of the vertebrae and the spinal nerves that exit the vertebrae. It also allows your discs to bulge out toward the back and overstretches your back muscles. Keeping your back muscles, or any muscles, lengthened by poor posture weakens them. Moreover, because your abs attach to your pelvic bone in front, too much muscle tension from abs, unbalanced by low back muscles, pulls your pelvis forward into a tilt that adds to back pain. You won’t feel a problem right away – this kind of back injury takes time to develop.
What Really Works Your Abs?
One approach to improving your abdomen is to go to a gym and neglect your abs the other 23 hours a day. It sometimes works. Another plan is to use your abs all day. Contract your abs tightly right now. Now let them bulge out completely loose. Somewhere between the two is a good tension to maintain for daily wear. When you stand up, notice if you sway backward. If you do, add tension to your abs to bring you upright. If you slouch forward, lift back and up and pull in your abdomen. Test your posture while standing with your back against a wall. No need to be a soldier, just see if your head, upper back, behind, calves and heels all touch at once. Sit upright without slouching or rounding your back. Stand and sit well all the time and you’ll exercise your abs without working out. To add more work your abs do trunk flexion, also called trunk curls or crunches.
Strength and endurance are separate systems and respond to different training. Strength means generating a high force in a single or concentrated effort. With endurance you can sustain light force over extended time.
To gain strength your muscles must contract at tensions close to their maximum, a concept called overloading. You need heavy resistance with few repetitions to overload a muscle. How heavy? A weight heavy enough that it can’t be lifted or moved more than eight times. If eight to ten crunches are your limit, then your body weight alone will increase strength. Do three sets of eight crunches three times a week. If you can continue past ten repetitions you’ll increase endurance more than strength. Overload for strength by keeping the repetitions under ten and using a slant board or adding weight to your chest. To gain endurance do lots without extra weight.
Don’t secure your feet under anything. That brings your hip flexors back into play. Curl forward with your abdominal muscles, not your neck. Clasp your hands on your chest or hold them beside your head to avoid pulling your neck forward. Don’t throw yourself forward with your arms, that’s cheating. To exercise your obliques twist to either knee.
To target the lower fibers of your abdominal muscles, lie on your back, knees bent, feet off the floor. Keep the back of your head on the floor, resting on your hands. Feel where the small curve of your lower back raises slightly off the floor. Then push your lower back into the floor by contracting your lower abdomen tightly. When you release, your back returns to a small arch. Don’t bend your legs to your trunk, that’s hip flexion, not abdominal work. Want a toughie? Lie on your back, flexed at the hip, both legs straight up. Contract your abdominal muscles to raise your hips from the floor. Again, don’t bend your legs closer to your trunk. Lift your legs straight up.
How Do You Flatten Your Abdomen?
Will abdominal exercise flatten your abdomen? There is no repetitive spot exercise that selectively removes fat from any target body part. If it could, people would have thin mouths from all their talking. To lose fat from your middle, run, swim, bike, row, dance, skate or walk. Aerobic exercise reduces body fat overall, including your middle. Ab exercise burns very few calories and will not take fat off your middle but helps compress your abdomen. Slouching and letting abdominal contents protrude past weak abs bunches fat to make your middle look rounder, so stand up straight and suck it in. (Your mother may have mentioned this!)
How Do You Get A Washboard?
Bands of fibrous tissue called fascia span the width of your rectus abdominis at intervals. With abdominal exercise, good posture, adequate carbohydrate and water in your diet, and reduced fat under your skin, your abs will poke through the fascia to produce a beautiful washboard tummy.