Blog post from our board member Dr. Stephen Black: Training The Core
With more of your members exercising for specific results, core stability training can help them improve athletic performance, and better perform activities of daily living.
From soccer to cycling, basketball to ballroom dancing, abdominal and low-back strength are essential for getting the most out of life, promoting fitness and reducing the risk of injury. The posture muscles are responsible for keeping the body in proper alignment (head level and back, chest out and stomach in), stabilizing the pelvis and providing an efficient transfer of power to the arms and legs. Equally important for athletes and other active people, core strength allows people to do more with less effort.
Stabilization programs aim to use the musculoskeletal system to protect spinal joint structures from repetitive microtrauma, recurrent pain and injury, while promoting improved athletic and lifestyle activities. Core training programs have become the latest trend within the health and fitness industry.
BODY RESPONSES TO RESISTANCE TRAINING
Consider the following relationships within the body when designing and implementing core stability programs for your members.
Nervous-system training. Perhaps the most overlooked aspect of strength training is the development of the nervous system.
The purpose of nervous-system training is to teach the body to recruit, preferentially, high-threshold motor units, improve inter/intra-muscular coordination, increase motor-unit firing rates, and to decrease inhibition or increase excitation from the central nervous system. Motor units are recruited and stressed based on a variety of stimuli, so adaptations to training made by motor units, and by the whole muscle, vary with the type of training stimuli.
Variability in movement patterns. Changing the biomechanics of an exercise, such as the angle of the body in relation to the load, hand and foot positions, and movement pathways, can introduce new challenges to the body, even if the exercise performed is quite similar. Moreover, different types of movement may cause different muscle compartments or synergistic muscles to become more or less active. In these cases, the nervous system is forced to reorganize the contraction patterns or tap into different motor unit pools that may further promote strength, balance and coordination.
Training supporting/stabilizer muscles. It is often assumed that plateaus in training progression are due to a limited adaptive response from the prime movers. However, stabilizer and support muscle adaptations are important for strength, balance and coordination improvements. Weak or neurally untrained stabilizers may be overloaded quickly and send inhibitory signals, resulting in a decreased neural drive to the prime movers. It is foreseeable that specific work for the stabilizer or neutralizer muscles may subsequently enable higher-intensity training for the prime movers.
Exercise variation. It is important to vary exercise selection regularly, possibly changing the exercise types every four to eight workouts. All muscles should be trained continually; however, different movements may be chosen to allow the nervous system to recover from performing a particular exercise. In addition, varying concentric, eccentric and even isometric contraction modes leads to specific neural adaptations.
The SAID principle. Specific adaptation to imposed demands (SAID principle) is an important consideration when designing strength programs. Since individuals’ backgrounds and the characteristics of their goals vary considerably, strength training must be specific enough to meet their individual needs. The current data suggests that it is the appropriate sequence and combination of exercises that produces superior results, and not simply the order of exercises, amount of work or number of repetitions accomplished.
CORE STRENGTH BASICS
Core strength has two basic benefits: improved exercise technique and better economy of movement. For example, when runners have weak core muscles, their hips tilt from side to side as they run. Core strength improves technique because the limbs are better supported. Improved strength in these posture muscles also allows more efficient movement by using fewer muscles, less oxygen and less energy. In other words, this type of strength helps exercisers achieve a higher level of endurance because the body isn’t fighting itself via compensatory motion.
The abdominals and low-back muscles are the secondary muscles for core stability. A “six pack” does not ensure core stability; in fact this creates inefficiencies within the functionality of the musculoskeletal system. The primary muscles are the pelvic floor muscles and the deep six of the hip rotators. Additionally, the sequential contraction of the muscles are essential for optimal core stabilization. If these muscles do not fire in the appropriate sequence, spinal stability does not occur. This is the shortcoming of many “core” programs. The participants, most likely, do not have the body awareness or muscle tone to appropriately contract specific muscles in the correct order to accomplish stabilization.
Even minor improvements in core strength can lead to big improvements in performance and enjoyment. Take running for example: If stronger abdominal and back muscles help stabilize the pelvis, the stride length will be symmetrical and appropriate in length, resulting in increased efficiency, decreased metabolic demands and, ultimately, decreased times. The same kind of results apply to many other sports. Of equal importance is the improved efficiency of activities of daily living.
SAMPLE EXERCISES FOR CORE STRENGTH
Following is a series of 11 exercises designed to help improve core strength. All that is needed is a mat or a carpeted space big enough to lie down. The best part of this program is that it takes less than one hour a week (15 minutes, three times a week). Keep in mind that simple is better when dealing with the deconditioned market. Also, age is no barrier to entry into the realm of core stability. As with all strength programs, exercisers may feel some discomfort performing these exercises, and possibly some soreness the day after; that’s normal. Sharp, stabbing or searing pain is not normal.
Kegel exercises. Kegel exercises are a wonderful way to initiate the activation and strengthening of the pelvic floor muscles, which will lead to increased core stabilization. A Kegel is the name of a pelvic floor exercise, named after Dr. Kegel. Pelvic, muscles are attached to the pelvic bones and act like a hammock, holding in the pelvic organs. To isolate these muscles, have clients try to stop and start the flow of urine. Kegel exercises can be performed by both men and women, but are usually associated with childbirth, and are most popular to treat incontinence. The success of Kegel exercises depends on proper technique and adherence to a regular resistance exercise program.
Bottoms up. Have clients lie on their back with their legs straight up in the air, their toes pointing at the ceiling and their arms by their sides for balance. They should pull their stomachs in like they’re trying to get into a tight pair of pants, and gently lift their butt about 3 inches off the ground. The movement should be smooth, gently curling their lower spine up and down. Make sure they don’t push down with their arms or bounce up and down. The idea is to isolate their lower abdominal muscles as much as possible. The tendency with this exercise is to allow the legs to migrate toward the head; the key to success is to have exercisers push their legs straight up as they roll the pelvis. Actually, the key to all core stabilization is not the exercise, but the technique.
Dead bugs. Clients should lie on their back with their knees bent and shins parallel to the floor. Have them gently tilt their pelvis so their tailbone is barely touching the ground. From this position, have them pull up with their abdominal muscles so their head, neck and upper back come off the ground, making sure they keep their back as flat as possible throughout the movement, and they keep their chin off their chest. (Have them pretend there is an orange between their chin and chest.) Make sure they don’t lace their fingers behind their head; instead, have them put their fingers by their ears or rest their palms on the sides of their head. This is better done with the arms crossed across the chest, pushing the chest and chin toward the ceiling.
Regular crunch. Have clients lie on their back with their knees bent, their feet flat on the floor, and their arms by their head or across their chest. Keeping their upper back as straight as possible, have them lift their head, neck and chest off the floor (withthat imaginary orange in place). Exercisers should focus on bringing their upper back only a few inches off the ground, should press the small of the back into the floor to maintain a neutral pelvis and should tighten the abs prior to initiation. They should perform as many as they can comfortably.
Hip raisers (both legs). Exercisers should lie on their back with their knees bent, both feet flat on the floor, their arms by their sides and their feet about shoulder width apart. From this position, have them gently pull their abdominal muscles in and tilt their pelvis toward the ceiling until they flatten the natural arch of their lower back. Next, have them push their feet into the floor and lift their back off the ground. If they’re doing everything correctly, their body should form a straight line from the shoulders to the knees. Now, have them return their body to the floor with their back as straight as possible, and repeat the exercise until they feel fatigued.
Hip raisers (one leg). Follow the instructions for regular hip raisers. Once exercisers have their body in a straight line, have them straighten one of their legs and point their toes. Keeping their hips level and their thighs parallel to each other, they should then slowly lower their hips to the floor, and come back up just before they reach the floor. Have them repeat this until they feel fatigued, and then have them switch legs. The exercise can also be initiated with one leg straight.
Oblique crunch. The object of this exercise is to strengthen the muscles on the sides of the abdomen (abdominal obliques). Have clients lie on their side with both legs bent, their knees together and their hands on the sides of their head. Next, have them gently pull up until their side lifts off the floor. (Make sure they keep their spine as straight as possible.) Have them continue until they feel fatigued, then have them roll over and repeat on the other side.
Twenty-one (or 18, 15, 12, 9, 6 or 3). This exercise incorporates seven regular crunches, seven half sit-ups and seven regular sit-ups. Have exercisers start with seven regular crunches, then have them sit all the way up and perform seven half sit-ups. Their back should be straight as they lower themselves until their body forms a 45-degree angle with the floor, and then come back up. After they have completed these, have them perform seven regular sit-ups.
The board. This is the most difficult exercise of the group. Exercisers should lie on their stomach with their feet and legs together, their toes in a push-up position and their head to one side. From this position, have them put their forearms on the floor and balance their body on their elbows and forearms. (Their body should be straight from their head to their heels.) The goal is to keep their entire body straight for one minute. It’s not as easy as it looks, so you may have your clients start out with 20-, 30- or 45-second intervals and work their way up to one minute.
Airplane. Clients should lie on their stomach with their legs and feet together, and their arms out to the side like airplane wings. From this position, have them contract the muscles of their arms, legs, back and butt, and lift their head, chest, arms and legs off the floor. Have them look up and pull their shoulders back as far as they will go. They should hold this position for 10 to 20 seconds.
Cobra. This exercise is a yoga posture, and is an excellent way to stretch the back and abdominal muscles. Haveclients lie on their stomach with their legs and feet together, and arms at their side. Next, have them place their palms on the ground and gently lift their head. Pressing down with their palms, they should feel a wave of contraction slowly move down their spine. Make sure they don’t force it. In the ideal cobra position, the arms are slightly bent, the top of the head points toward the ceiling, and the back has a fluid, comfortable arch.
Flat-back toe touch. This is an excellent complement to the cobra stretch. Sitting on the floor with their legs out in front of them, have exercisers bend at the waist (not in the spine) and touch their toes. The point of this exercise is to stretch the hamstring muscles, so clients can bend their knees if they can’t keep their back and legs straight at the same time. Have them hold this stretch for as long as it feels comfortable.
REFERENCES
Andersson, E., Z. Ma, J. Nilsson and A. Thorstensson. Abdominal and hip flexor muscle involvement in various training exercises. Proceedings from the 12th International Congress of Biomechanics. Los Angeles, 1989.
Basmajian, J.V., and C.J. DeLuca. Muscles Alive: Their functions revealed by electromyography, 5th ed. Williams & Wilkins: Baltimore, 1985.
Bearn, J.G. The significance of the activity of the abdominal muscles in weight lifting. Acta Anatomica 45: 83-89, 1961.
Bogduk, N. Clinical Anatomy of the Lumbar Spine and Sacrum, 3rd ed. Churchill Livingstone: Edinburgh, 1997.
Kapanji, I.A. The Physiology of the Joints: The trunk and vertebral column. Chruchill Livingstone: Edinburgh, 1974.
Kendall, F.P., and E.K. McCreary. Muscles: Testing and Function, 3rd ed. Williams & Wilkins: Baltimore, 1983.
Stephen A. Black, M.Ed., P.T., A.T.C/L., N.S.C.A./C.P.T., director, Health and Fitness Institute, Stamford, Conn., and CEO of RockyMountain Human Performance Center Inc., Boulder, Colo., provides individualized programs for athletes, weekend warriors and post-rehab clients. Black has 20-plus years’ experience in the health and wellness industry, and has worked with professional teams including NFL, NBA, NHL, WNBA and ABL/NBL affiliates. He is also a presenter for the health and wellness industry.