Eccentric training

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Eccentric training is defined as active contraction of a muscle occurring simultaneously with lengthening of the muscle . For example, in a biceps curl the action of lowering the dumbbell back down from the lift is the eccentric phase of that exercise — as long as the dumbbell is lowered slowly rather than letting it drop (i.e the bicep muscle is in a state of contraction to control the rate of descent of the dumbbell).

There are three distinct phases in the movement of muscles and tendons: isometric (no movement), concentric (contracting) and eccentric (extracting). All three of these stages in muscles movements have an effect on muscle tissues and tendons (tendons are what attach the muscle to the bone).

Eccentric training focuses on slowing down the elongation of the muscle process in order to challenge the muscles, which can lead to stronger muscles, faster muscle repair and increasing metabolic rate.[1]

Eccentric movement provides a braking mechanism for muscle and tendon groups that are experiencing concentric movement to protect joints from damage as the contraction is released.[1]

Eccentric training is particularly good for casual and high performance athletes or the elderly and patients looking to rehabilitate certain muscles and tendons.[2]

Negative movement[edit]

This movement has also been described as negative training. This “negative” movement is necessary to reverse the muscle from its initial trajectory.[1]

When weight exceeds the force developed by the muscle, as in an eccentric muscle action, the exercise is referred to as negative work because the muscle is absorbing energy in this loaded position.[1]

It goes on to state that eccentric contractions use less energy, even though they create more force than concentric actions.[1]

History[edit]

Adolf Fick originally discovered in 1882 that “contracting muscle under stretch could produce greater force than a shortening muscle contraction” like in concentric movements. Fifty years later, A.V. Hill determined that “the body had lower energy demand during an eccentric muscle contraction than during a concentric muscle action”.[3]

Erling Asmussen first introduced eccentric training in 1953 as “excentric,” with ex meaning “away from” and centric meaning “center.” Hence, the term was coined to mean a muscle contraction that moves away from the center of the muscle.[3]

But the first revelation of the functional significance of these properties occurred by way of a clever demonstration devised by Bud Abbott, Brenda Bigland, and Murdoch Ritchie. They connected two stationary cycle ergometers back-to-back with a single chain, such that one cyclist pedaled forward and the other resisted this forward motion by braking the backward-moving pedals. Because the internal resistance of the device was low, the same force was being applied by both individuals, yet the task was much easier for the individual braking. This demonstration cleverly revealed that a tiny female resisting the movement of the pedals could easily exert more force than, and hence control the power output of, a large burly male pedaling forward.[3]

Energy[edit]

During the eccentric phase of movement, the muscle absorbs energy. This work is done “by stretching the muscle and in this process the muscle absorbs mechanical energy”.[3]

This mechanical energy is dissipated or converted into one or a combination of two energies.

  • 1. Heat
  • 2. Elastic Recoil

Heat[edit]

The energy that is absorbed by the muscle will be dissipated as heat if the muscle is being used as a “damper or shock absorber”. This leads to increase in body temperature.[3]

Elastic Recoil[edit]

The energy that is absorbed by the muscle can be converted into elastic recoil energy, and can be recovered and reused by the body. This creates more efficiency because the body is able to use the energy for the next movement, decreasing the initial impact or shock of the movement.[3]

For example, kinetic energy is absorbed in running every time your foot strikes the ground and continues as your mass overtakes the foot. At this moment, elastic recoil energy is at its maximum and a large amount of this energy is absorbed and is added to the next stride.[3]

This movement is similar to the action of springs, where the muscle is continually shortened and stretched resulting in enhanced effectiveness and force. It can lead to the perception of “less effort” even though dealing with higher force.[4]

But time matters in elastic recoil. If this energy is not used quickly it is dissipated as heat. The role of eccentric training is to use these principles of energy conversion to strengthen muscle and tendon groups.[3]

Physiological mechanisms[edit]

The muscle has “tension producing tissue comprising small contractile units referred to as sarcomeres” that each contain a “thick (myosin) and thin (actin) myofilament (muscle filaments or proteins) that overlaps to format a cross-bridge bond (attachment)”.[1]

When in a concentric exercise, shortening of a muscle occurs as the myosin and actin cross bridges repeatedly attach and detach to draw the actin across the myosin — creating force. Each cross-bridge attachment and detachment cycle is powered by the splitting of one molecule of adenosine triphosphate (ATP). Examples of such exercises include kicking a ball or lifting a weight.[1]

In controlled release reversals of such concentric motions, the eccentric movement stretches the muscle with opposing force that is stronger than the muscle force. When myofilaments of the muscle fiber are stretched in such eccentric contractions there can be reduced numbers of detachments of cross bridge myosin and actin links. With more cross bridges remaining attached there is greater force production in the muscle. Examples of activities involving eccentric muscle contraction include walking down a hill or resisting the force of gravity while lowering a heavy object.[1]

“Eccentric actions place a stretch on the sarcomeres to the point where the myofilaments may experience strain, otherwise known as exercise induced delayed onset muscle soreness (DOMS)” (Aaron Bubbico & Len Kravitz, 2010). One area of research that has much promise in relation to DOMS and eccentric exercise is the repeated-bout effect (RBE). To help prevent or lessen DOMS from eccentric exercise, or to facilitate recovery from it, the exerciser would eccentrically stimulate the muscle then repeat at weekly intervals to build up strength and allow the strain (in response to a given force level) to reduce over time.[1]

Scientific Research[edit]

Several different studies have been conducted testing the hypothesis of eccentric training and its benefits. The first commercial eccentric trainer, the Quadmill, is the machine that has been used to test the benefits of eccentric training in the article named AN INITIAL ASSESSMENT OF THE METABOLIC COST OF USING THE QUADMILL by Howlett K., T. Keniston, A. Grassl, A. Olsson, C. Eidem, and D.J. McCann from Department of Exercise Science, Gonzaga University, Spokane, WA. [5]

Their experiment set out to determine the “metabolic cost of exercise on a novel piece of equipment called the Quadmill”. The Quadmill requires the subject to stand in a stationary position on a platform that “oscillates in the vertical and horizontal planes”. The rate of oscillation directly determines the intensity of the exercise, and therefore translates to a stronger workout on the lower body extremities. [6]

During the study, it was hypothesized that the overall metabolic response would be “directly proportional to both body mass and rate of oscillation”. By increasing the rate of oscillation, it was believed, total cost would increase proportionately. However, contrary to the hypothesis, testing found that “there was no apparent relationship between body mass and the total oxidative cost at any of the three intensities (tested)”. Consequently, the conclusions were that “the oxidative response to the exercise occurred during both the exercise and recovery periods” leading to the conclusion that “the device induces a significant anaerobic response that is rate dependent and independent of body mass”. . [7]

Muscle injury[edit]

Eccentric contractions are a frequent cause of muscle injury when engaging in unaccustomed exercise. But a single bout of such eccentric exercise leads to adaptation which will make the muscle less vulnerable to injury on subsequent performance of the eccentric exercise.[8]

Findings[edit]

Several key findings have been researched regarding the benefits of eccentric training:

  • Eccentric training creates greater force owing to the “decreased rate of cross-bridge muscle detachments.” Patients and athletes will have more muscle force for bigger weights when eccentric training.[1]
  • Eccentric contractions use less energy and actually absorb energy that will be used as heat or elastic recoil for the next movement.[1]
  • Increased DOMS leads to more tenderness in eccentric, rather than pure pain or tendon swelling amongst patients.[1]
  • Repeated-bout Effect markedly reduces DOMS. “Completing bouts of eccentric training and then repeating the workout 1 week (or more) later will result in less DOMS after the second workout.”[1]
  • Older individuals are less vulnerable to injury from eccentric exercise, primarily because of the reduced strain on muscle-tendon groupings as compared to traditional concentric exercise.[1]
  • Stretching of the muscles and eccentric training provides protection from injury or re-injury.[1]
  • Eccentric training has proven to be an excellent post rehabilitation intervention for lower-body injuries.[1]
  • Subjects report less weariness from eccentric training than from concentric training.[1]
  • Total body eccentric training can raise resting metabolic rate by about 9 per cent, with the greatest magnitude in the first two hours.[1]
  • While energy costs remain low, the degree of force is very high. This leads to muscles that respond with significant increases in muscle strength, size and power.[1]

Sports and rehabilitation[edit]

With eccentric training, muscles are able to create more for less work, which has special meaning in the realms of high performance sports — both for injury prevention and optimal-performance training. For athletes and sports enthusiasts, this eccentric model can help with explosive force[9] training in order to prevent injuries or recurring injuries, and trains the body to use the kinetic force driven by eccentric training more efficiently.[10] Canadian Olympian Kim St. Pierre [11] uses eccentric training as part of her regime. The Esmonde Technique takes eccentric training and makes it available to the masses through Classical Stretch and Essentrics. After having hip surgery in the summer of 2007, St.Pierre began to practice the Esmonde Technique with experts Miranda Esmonde-White from PBS’s Classical Stretch and Sahra Esmonde-White host of the Essentrics workout in order to heal her hip.[12]

According to tests, increases in both strength and muscle fiber are higher in eccentric training than in traditional concentric training.[13]

The rehabilitative nature, low energy costs, high magnitudes of force, and low uptake of oxygen all align eccentric exercise for both the elderly and rehabilitative functions.[2]

In old age, loss of strength and muscle mass is commonplace. Add to these factors disease and cardiac and respiratory illness. Eccentric training enables the elderly, and those with the same problems, the ability to train muscle groups and increase strength and resiliency with low-energy exercise.[2]

Eccentric training has been found to be beneficial to those with a variety of physical ailments.[14]

Anterior Cruciate Ligament (ACL) damage[edit]

Tearing an ACL in the knee causes serious damage that can last several years and often requires surgery. The ACL is one of the four main stabilizing ligaments of the knee. During the post-operative rehabilitation of patients, eccentric training can be used as a cornerstone of developing muscle size and strength. According to tests conducted J. Parry Gerber in 2007, structural changes in the muscles greatly exceeded those achieved with standard concentric rehabilitation. The success of the involvement of gradual progressive exposure to negative work ultimately led to the production of high muscle force.[15]

Sarcopenia[edit]

Sarcopenia is the progressive loss of muscle mass due to aging. Muscle mass begins to deteriorate as early as the age of 25, and consistently deteriorates into old age. By the age of 80 “one half of the skeletal muscle has been lost” (Lastayo, Woolf, Lewek, Snyder-Mackler, Reich & Lindstedt, 2003). With this great decrease in mass, strength is also decreased. Eccentric training has the ability to counteract sarcopenia through sustained training. The unique trait of greater overloads to the muscle with less strenuous impact on the body, as well as cardiac and respiratory systems, offers a unique case for the elderly. The high-force and low-cost set of attributes in eccentric exercise makes it ideal for the actively impaired.[16]

Muscle tendon injuries[edit]

The entire muscle-tendon system works cohesively to slow down limb movement. The close relationship between the muscle and tendons help to dissipate heat or temporarily store kinetic energy. If the forces needed to slow down a limb exceed the capacity of the muscle-tendon system injury is likely to occur.

Athletes with recurring hamstring and abductor muscle injuries have greater impairment of eccentric strength, suggesting that improvements in eccentric training may minimize the risks of injury by strengthening the muscle-tendon groupings in high-stress areas of the body.

Eccentric training is of huge benefit to those that wish to avert injuries by improving the muscles abilities to absorb more energy before deteriorating. According to one article, “Increased stiffness in tendons, greater force at failure, and an improved ability to absorb energy at the musculotendonous junction result following eccentric exercise training”.[17]

Osteopenia[edit]

Usually viewed as a precursor to osteoporosis, Osteopenia is when bone density is lower than normal levels. Bone mass is affected by muscles forces and their loads to the bone structure. The strength and density of the bone is directly influenced by local strain. Due to the high strain on muscles during eccentric training, coupled with low energy output, eccentric training becomes a cornerstone of the rehabilitative process.[17]

Tendinoses[edit]

Intense repetitive activities tend to create chronic tendon disorders, where the tendons become injured, inflamed or ruptured. While typically these disorders are directly related to eccentric muscle movements, the ability for a muscle to strengthen and prevent injury through eccentric training is great. Controlled rehabilitative regimes will actually strengthen and repair tendons. Ample evidence supports the notion that the tendon, like the muscle, can adapt favorably to physical stress and eccentric loads.[18]

It has been deduced that high muscle tendon forces delivered in a controlled environment are needed for optimal tendon adaptation. While eccentric stress is related to the injury, high force eccentric exercises are needed to maximize recovery.[19]

Chronic Patellar Tendonitis[edit]

A condition that arises when the tendon and the tissues that surround it, become inflamed and irritated. This is usually due to overuse, especially from jumping activities. This is the reason chronic patellar tendonitis is often called “jumper’s knee.” A study done by Roald Bahr and colleagues looked at which method of tendon rehabilitation exercise — the “eccentric squat” exercise or the universal gym “leg extension/leg curl” — produced more recovery results in terms of recovery in the treatment of chronic patellar tendonitis. On the twelve week exercise program, participants were tested for thigh circumference and quadriceps and hamstring moment of force. There was no significant difference between the groups in either quadriceps or hamstring moment of force and hamstring moment of force significantly increased in both groups, but the eccentric squat saw significantly lower pain ratings and produced twice as many “pain free” subjects at the end of the program than the other group.[20]

References[edit]

  1. ^ a b c d e f g h i j k l m n o p q r s Bubbico, Aaron and Kravitz, Len, Ph.D, October 2010 "Eccentric Training", Idea Fitness Journal, Volume 7, Number 10.
  2. ^ a b c Lindstedt, S. L., LaStayo, P.C., and Reich, T.E., December 2001, "When Active Muscles Lengthen: Properties and Consequences of Eccentric Contractions", New Physiol. Sci , Volume 16, p. 260
  3. ^ a b c d e f g h Lindstedt, S. L., LaStayo, P.C., and Reich, T.E., December 2001, "When Active Muscles Lengthen: Properties and Consequences of Eccentric Contractions", New Physiol. Sci , Volume 16, p. 256.
  4. ^ LaStayo, Paul C., Ewy, Gordon A., Pierotti, David D., Johns, Richard K., Lindstedt, Stan, May 2003, "The positive effects of negative work: increased muscle strength and decreased fall risk in a frail elderly population", Journal of Gerontology, Volume 58A, Number 5, p. 419.
  5. ^ Howlett K., T. Keniston, A. Grassl, A. Olsson, C. Eidem, and D.J. McCann, January 2011 [AN INITIAL ASSESSMENT OF THE METABOLIC COST OF USING THE QUADMILL ] Department of Exercise Science, Gonzaga University, Spokane, WA.
  6. ^ Howlett K., T. Keniston, A. Grassl, A. Olsson, C. Eidem, and D.J. McCann, January 2011 [AN INITIAL ASSESSMENT OF THE METABOLIC COST OF USING THE QUADMILL ] Department of Exercise Science, Gonzaga University, Spokane, WA.
  7. ^ Howlett K., T. Keniston, A. Grassl, A. Olsson, C. Eidem, and D.J. McCann, January 2011 [AN INITIAL ASSESSMENT OF THE METABOLIC COST OF USING THE QUADMILL ] Department of Exercise Science, Gonzaga University, Spokane, WA.
  8. ^ Clarkson PM1, Hubal MJ (2002). "Exercise-induced muscle damage in humans". AMERIAN JOURNAL OF PHYSICAL MEDICINE & REHABILITATION 81 (11 Suppl): S52–S69. PMID 12409811. 
  9. ^ Aagaard, Per, "The Use of Eccentric Strength Training to Enhance Maximal Muscle Strength, Explosive Force (RDF) and Muscular Power - Consequences forAthletic", The Open Sports Sciences Journal, 2010, Volume 3, p. 53
  10. ^ LaStayo, Paul C. Ph.D, Woolf, John M., Lewek, Michael D., Snyder-Mackler, Lynn, Trude-Reich, Lindstedt, Stan L. Ph.D, October 2003, "Eccentric Muscle Contractions: Their Contribution to Injury, Prevention, Rehabilitation, and Sport", Journal of Orthopaedic & Sports Physical Therapy, Volume 33, Number 10, p. 557
  11. ^ "Kim St. Pierre". Wikipedia. 
  12. ^ "Goalie St.Pierre Takes A Page From The Ballet World". TSN. April 17, 2009. 
  13. ^ Roig, M., O’Brien, K., Kirk, G., Murray, R., McKinnon, P., Shadgan, B., Reid, W.D., 2009, "The effects of eccentric versus concentric resistance training on muscle strength and mass in healthy adults: a systematic review with meta-analysis", British Journal of Sports Medicine, Volume 43, pp. 556-568.
  14. ^ LaStayo, Paul C. Ph.D, Woolf, John M., Lewek, Michael D., Snyder-Mackler, Lynn, Trude-Reich, Lindstedt, Stan L. Ph.D, October 2003, "Eccentric Muscle Contractions: Their Contribution to Injury, Prevention, Rehabilitation, and Sport", Journal of Orthopaedic & Sports Physical Therapy, Volume 33, Number 10, pp. 557-571.
  15. ^ Gerber, J. Parry, Marcus, Robin L., Dibble, Leland E., Greis, Patrick E., Burks, Robert T. and LaStayo, Paul C., March 2007, "After Anterior Cruciate Ligament Reconstruction Effects of Early Progressive Eccentric Exercise on Muscle Structure", The Journal of Bone and Joint Surgery, Volume 89, pp. 559-57.
  16. ^ LaStayo, Paul C. Ph.D, Woolf, John M., Lewek, Michael D., Snyder-Mackler, Lynn, Trude-Reich, Lindstedt, Stan L. Ph.D, October 2003, "Eccentric Muscle Contractions: Their Contribution to Injury, Prevention, Rehabilitation, and Sport", Journal of Orthopaedic & Sports Physical Therapy, Volume 33, Number 10, p. 561.
  17. ^ a b LaStayo, Paul C. Ph.D, Woolf, John M., Lewek, Michael D., Snyder-Mackler, Lynn, Trude-Reich, Lindstedt, Stan L. Ph.D, October 2003, "Eccentric Muscle Contractions: Their Contribution to Injury, Prevention, Rehabilitation, and Sport", Journal of Orthopaedic & Sports Physical Therapy, Volume 33, Number 10, p. 562.
  18. ^ LaStayo, Paul C. Ph.D, Woolf, John M., Lewek, Michael D., Snyder-Mackler, Lynn, Trude-Reich, Lindstedt, Stan L. Ph.D, October 2003, "Eccentric Muscle Contractions: Their Contribution to Injury, Prevention, Rehabilitation, and Sport", Journal of Orthopaedic & Sports Physical Therapy, Volume 33, Number 10, p. 563.
  19. ^ LaStayo, Paul C. Ph.D, Woolf, John M., Lewek, Michael D., Snyder-Mackler, Lynn, Trude-Reich, Lindstedt, Stan L. Ph.D, October 2003, "Eccentric Muscle Contractions: Their Contribution to Injury, Prevention, Rehabilitation, and Sport", Journal of Orthopaedic & Sports Physical Therapy, Volume 33, Number 10, p. 564.
  20. ^ Bahr, Roald, Fossan, Bjorn, Loken, Sverre, and Engebretsen, Lars, August 2006, "Surgical Treatment Compared with Eccentric Training for Patellar Tendinopathy (Jumpers Knee) A Randomized Controlled Trial", The Journal of Bone and Joint Surgery, Volume 88A, Number 8, pp. 1689-1698.

Sources[edit]

  • Aagaard, Per, "The Use of Eccentric Strength Training to Enhance Maximal Muscle Strength, Explosive Force (RDF) and Muscular Power - Consequences for

Athletic", The Open Sports Sciences Journal, 2010, Volume 3, pp. 52–55.

  • Bahr, Roald, Fossan, Bjorn, Loken, Sverre, and Engebretsen, Lars, August 2006, "Surgical Treatment Compared with Eccentric Training for Patellar Tendinopathy (Jumpers Knee) A Randomized Controlled Trial", The Journal of Bone and Joint Surgery, Volume 88A, Number 8, pp. 1689–1698.
  • Bubbico, Aaron and Kravitz, Len, Ph.D, October 2010 "Eccentric Training", Idea Fitness Journal, Volume 7, Number 10.
  • Gerber, J. Parry, Marcus, Robin L., Dibble, Leland E., Greis, Patrick E., Burks, Robert T. and LaStayo, Paul C., March 2007, "After Anterior Cruciate Ligament Reconstruction Effects of Early Progressive Eccentric Exercise on Muscle Structure", The Journal of Bone and Joint Surgery, Volume 89, pp. 559–57.
  • LaStayo, Paul C., Ewy, Gordon A., Pierotti, David D., Johns, Richard K., Lindstedt, Stan, May 2003, "The positive effects of negative work: increased muscle strength and decreased fall risk in a frail elderly population", Journal of Gerontology, Volume 58A, Number 5, pp. 419–424.
  • LaStayo, Paul C. Ph.D, Woolf, John M., Lewek, Michael D., Snyder-Mackler, Lynn, Trude-Reich, Lindstedt, Stan L. Ph.D, October 2003, "Eccentric Muscle Contractions: Their Contribution to Injury, Prevention, Rehabilitation, and Sport", Journal of Orthopaedic & Sports Physical Therapy, Volume 33, Number 10, pp. 557–571.
  • Lindstedt, S. L., LaStayo, P.C., and Reich, T.E., December 2001, "When Active Muscles Lengthen: Properties and Consequences of Eccentric Contractions", New Physiol. Sci , Volume 16, pp. 256–261.
  • Roig, M., O’Brien, K., Kirk, G., Murray, R., McKinnon, P., Shadgan, B., Reid, W.D., 2009, "The effects of eccentric versus concentric resistance training on muscle strength and mass in healthy adults: a systematic review with meta-analysis", British Journal of Sports Medicine, Volume 43, pp. 556–568.
  • Howlett K., T. Keniston, A. Grassl, A. Olsson, C. Eidem, and D.J. McCann, January 2011 [AN INITIAL ASSESSMENT OF THE METABOLIC COST OF USING THE QUADMILL ] Department of Exercise Science, Gonzaga University, Spokane, WA.