An eccentric contraction is the active muscle movement as it extends under the load. Eccentric training repeatedly performs eccentric muscle contractions. For example, in a bicep curled up the act of lowering the dumbbell back down from the elevator is the eccentric phase of the exercise - as long as the dumbbell is lowered slowly than letting it fall (ie, the biceps are in a state of contraction to control the dumbbell rate).
Eccentric contractions are one of three distinct phases in muscle and tendon movement, the other two are isometric contractions (no movement), and concentric contractions (contractions).
Eccentric training focuses on slowing the extension of muscle processes to challenge the muscles, which can lead to stronger muscles, improve muscle more quickly and increase metabolic rate.
The eccentric movement provides a braking mechanism for the muscles and tendon groups that undergo concentric movements to protect the joint from damage when contractions are released.
Eccentric training is excellent for regular and high-performing athletes or parents and patients who want to rehabilitate certain muscles and tendons.
Video Eccentric training
Negative movement
This movement has also been described as negative training. This "negative" movement is needed to reverse the muscle from the initial path.
When the weight exceeds the strength developed by the muscles, as in the action of eccentric muscles, this exercise is called negative work because the muscles absorb energy in this loaded position.
Eccentric contractions use less energy, although they create more power than concentric action.
Maps Eccentric training
History
Adolf Fick was originally discovered in 1882 that "contracting muscles under stretch can produce greater strength than shortening muscle contractions" as in concentric movements. Fifty years later, A.V. Hill determined that "the body has lower energy demand during eccentric muscle contraction than during concentric muscle action".
Erling Asmussen first introduced the eccentric training in 1953 as "excentric," with ex meaning "far from" and centric meaning "center." Therefore, the term is created to mean the contraction of the muscle that moves away from the center of the muscle.
But the first revelation of the functional significance of these traits occurs by means of intelligent demonstrations made by Bud Abbott, Brenda Bigland, and Murdoch Ritchie. They connect two stationary back-to-back stationary ergometers with a single chain, allowing one cyclist to paddle forward and the other withholding this forward motion by braking the backward pedal. Because the internal resistance of the device is low, the same power is applied by both individuals, but the task is much easier for individual braking. This demonstration cleverly reveals that a small woman holding back the pedal movement could easily exert more power than, and therefore control the power output, a large, burly man pedaled forward.
Energy
During the eccentric phase of movement, the muscle absorbs energy. This work is done "by stretching the muscles and in this process the muscles absorb the mechanical energy".
This mechanical energy is dissipated or converted into one or a combination of two energies.
- Hot
- Elastic recoil
Heat
The energy absorbed by the muscle will dissipate as heat if the muscle is used as a "silencer or shock absorbers". This causes an increase in body temperature.
Elastic Recoil
The energy absorbed by the muscles 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 energy for subsequent movements, reducing initial impact or movement shocks.
For example, kinetic energy is absorbed in running every time a person's feet touch the ground and continues as a person's mass follows the foot. At this time, the elastic recoil energy is maximum and a large amount of this energy is absorbed and added to the next step.
This movement is similar to the action of springs, where the muscles continue to be shortened and stretched thus increasing their effectiveness and strength. This can lead to the perception of "little effort" despite dealing with higher forces.
But time is important in elasticity. If this energy is not used quickly it will disappear as heat. The role of eccentric training is to use energy conversion principles to strengthen muscles and tendon groups.
Physiological mechanism
Muscles have a "tissue-producing strain consisting of a small contractile unit called a sarcoma" each of which contains "myosin" and "actin" (overlapping muscle or protein filaments) to form cross-bridge bonds (attachment ) ".
When in concentric exercise, muscle shortening occurs when myosin and actin crossing bridges repeatedly attach and release to draw actin throughout the power of creating myosin. Each cross-bridge bond and detachment cycle is supported by the separation of one adenosine triphosphate molecule (ATP). Examples of such exercises include kicking a ball or lifting weights.
In a controlled reversal of such concentric movements, the eccentric movement extends muscles with opposing forces that are stronger than muscle strength. When myofilaments of muscle fibers are stretched in such eccentric contractions there can be a reduction in the number of cross bridge myosin detonations and actin links. With more cross-bridges remaining, there is a greater production of strength in the muscles. Examples of activities involving eccentric muscle contractions include walking downhill or against the force of gravity while lowering heavy objects.
"The eccentric action places stretching on the sarcometer to the point where myofilaments may be tense, otherwise known as a sport that induces delayed onset muscle pain (DOMS)" (Aaron Bubbico & Len Kravitz, 2010). One area of ​​promising research in relation to DOM and eccentric exercises is the repetitive effect (RBE). To help prevent or reduce DOMS from eccentric exercises, or to facilitate recovery from exercise, exercise will eccentrically stimulate muscles and repeat at weekly intervals to build strength and allow tension (in response to given strength levels) to reduce over time.
Muscle injury
Eccentric contractions are often the cause of muscle injury while doing unusual exercises. But a single attack of eccentric exercise leads to adaptation that will make the muscle less susceptible to injury to the performance of the next eccentric exercise.
Findings
Several key findings have been studied about the benefits of eccentric training:
- Eccentric training creates greater strength due to "decreased cross-bridge muscle detachment." Patients and athletes will have greater muscle strength for larger loads when training is eccentric.
- Eccentric contractions use less energy and completely absorb the energy to be used as heat or elastic for subsequent movement.
- Increased DOM causes more pain in eccentric, rather than pure pain or tendon swelling among patients.
- Effect Repeatedly significantly reduces DOM. "Resolving an eccentric training attack and then repeating a week of training (or more) will result in fewer DOMs after the second exercise."
- Older individuals are less susceptible to injuries from eccentric exercises, mainly because of reduced tension in the tendon-muscle groups compared to traditional concentric exercises.
- Muscle stretching and eccentric training provide protection from injury or back injury.
- Eccentric training has proven to be an excellent post-rehabilitation intervention for lower body injuries.
- The subjects reported less fatigue than eccentric training than from concentric training.
- Total body eccentric exercise can increase the rate of resting metabolism by about 9 percent, by the greatest amount in the first two hours.
- While energy costs remain low, the power level is very high. This leads to muscles that respond with a significant increase in muscle strength, size and strength.
Eccentric exercises
Eccentric exercise or resistance training is currently used as a form of rehabilitation for sports injuries, but also as an alternative form of exercise for the elderly, influenced by neurological disorders, COPD, cardiopulmonary disorders, and cancer. Muscle loss is a major problem faced by people suffering from the above disorders and many are unable to participate in strict training protocols. Eccentric muscle contractions produce high strength with low energy costs. According to HortobÃÆ'¡gyi because of these qualities the eccentric exercises have the greatest potential for muscle strengthening. To strengthen the muscles, external forces must exceed the muscles while it is elongated. The definition of eccentric contraction is almost the exact definition of muscle strengthening.
Perceived Muscle Damage: There are provisions regarding eccentric contractions because they cause muscle damage and injury. Eccentric contractions can cause delayed onset of muscle pain. contractions themselves do not cause muscle damage or injury.
Evidence of muscle strengthening without damage: One problem that often arises in ACL rehabilitation is to increase quadriceps muscle strength without getting injured again. In the beginning, high-style eccentric training can be used to increase muscle strength and volume without damaging the ACL graft, surrounding soft tissues, and articular cartilage. In an experiment conducted on mouse muscles after twenty sessions of low eccentric exercise intensity treadmill, the weight of muscle wet and fiber cross section was significantly greater than the control group and level. This result leads to the conclusion that low intensity eccentric contractions have the ability to "produce sufficient mechanical stress to induce muscle hypertrophy without over-stressing that can result in damage to muscle fibers." Other articles have found that muscle damage is not necessary to achieve hypertrophy. mechanical stress caused by the eccentric contraction is what causes hypertrophy in individuals undergoing eccentric training. Research done in the elderly shows that eccentric conditioners with low intensity can actually minimize muscle damage According to the Gault low energy costs, and low oxygen demand make low-intensity eccentric exercise is ideal for the elderly.
Eccentric Contraction and Oxygen Consumption: Oxygen consumption is necessary for the muscle to function properly. Eccentric muscle contractions are considered to work negatively because the muscles work with resistance. Negative work is the mechanical energy absorbed by the work done on the muscles when the force on the muscle is greater than the force generated. The experiment was done by biking. The amount of oxygen consumption is measured during the forward paddling movement as a positive job and pedaling with resistance as a negative work. Less oxygen is consumed during negative work then it positively works with the ratio of oxygen consumption to 3: 7. Due to the low oxygen consumption of the eccentric exercise study has been done in patients with severe COPD. The eccentric cycling exercise exercise was created for this patient and the results found no side effects, minimal muscle pain that had no effect on strength, and high adherence. In addition, other cycling research concludes that eccentric cycling is a safe alternative for COPD patients because they can perform high-intensity work at a lower cost.
Eccentric Contraction and Heart Output: With lower oxygen costs, how does the eccentric exercise affect the heart? A study was conducted to test how eccentric and concentric contractions affect the heart's autonomic modulation after exercise. Men (ages 18-30) are divided into four groups: concentric control, eccentric control, concentric training, and eccentric training. The results concluded that endurance training (eccentric contraction) increases strengthening. Increased heart vagal modulation during recovery was also concluded.
Much research has been done on eccentric exercises over the last decade. It can be said there is substantial evidence that eccentric exercise really exceeds concentric exercises for rehabilitation and training aspects, energy costs, oxygen consumption, and muscle strengthening.
Sports and rehabilitation
With eccentric training, muscle can create more for less work, which has a special meaning in the field of high-performance sports - both for injury prevention and optimal performance training. For athletes and sports fans, this eccentric model can help with explosive force training to prevent injuries or recurrent injuries, and train the body to use the kinetic power driven by eccentric training more efficiently. Canadian Olympic Kim St. Pierre uses eccentric training as part of his regime. The Esmonde technique takes on eccentric training and makes it available to the masses through Classical Stretching and Essentrics. After undergoing hip surgery in the summer of 2007, St.Pierre began practicing Esmonde Technique with Miranda Esmonde-White experts from PBS's Classical Stretch and Sahra Esmonde-White as the Essentrics training host to heal her hips.
According to tests, increased strength and muscle fibers are higher in eccentric training than traditional concentric training.
The rehabilitative nature, low energy costs, high force forces, and low oxygen uptake all align the eccentric exercises for both parents and rehabilitative functions.
In old age, loss of strength and muscle mass is common. Add to these factors diseases and heart and respiratory diseases. The eccentric training allows parents, and those who have similar problems, the ability to train muscle groups and increase strength and resilience with low energy workouts.
Eccentric training has proven to be beneficial for those with various physical ailments.
Anterior Cruciate Ligament Damage (ACL)
Tearing ACLs in the knee causes serious damage that can last several years and often requires surgery. The ACL is one of the four major knee stabilizer ligaments. During post-operative rehabilitation of patients, eccentric training can be used as a foundation for the development of muscle size and strength. According to tests conducted by J. Parry Gerber in 2007, structural changes in muscles exceeded that achieved with standard concentric rehabilitation. Successful involvement of progressive progressive exposure to negative work eventually leads to the production of high muscle strength.
Sarcopenia
Sarcopenia is a progressive loss of muscle mass from aging. Muscle mass begins to deteriorate as early as age 25, and has consistently worsened into old age. At the age of 80 "one half of skeletal muscle has disappeared" (Lastayo, Woolf, Lewek, Snyder-Mackler, Reich & Lindstedt, 2003). With this massive decrease in mass, power also decreases. Eccentric training has the ability to fight sarcopenia through ongoing training. The unique nature of the greater overload to the muscles with less severe impact on the body, as well as the heart and respiratory system, offers a unique case for the elderly. High-powered attributes and low cost in eccentric exercise make it ideal for active distractions.
Muscle tendon injury
The whole system of muscle tendons works cohesively to slow down the movement of the extremities. The close relationship between muscle and tendon helps to remove heat or store kinetic energy for a while. If the forces needed to slow the extremities exceed the capacity of the muscle tendon system, injury is likely to occur.
Athletes with hamstring injuries and recurrent muscular abductors have a greater eccentric strength disorder, suggesting that improvements in eccentric training can minimize the risk of injury by strengthening muscle-tendon groups in areas of high body stress.
Eccentric training is very useful for those who want to avoid injury by increasing muscle ability to absorb more energy before it gets worse. According to one article, "Increased stiffness of the tendon, greater strength on failure, and increased ability to absorb energy at musculotendonous junction results after eccentric exercise exercises".
Osteopenia
Usually seen as a precursor to osteoporosis, osteopenia is when bone density is lower than normal levels. Bone mass is affected by muscle strength and its load to the bone structure. Strength and bone density are directly affected by local strains. Due to the high tension in muscles during eccentric training, coupled with low energy output, eccentric training becomes the cornerstone of the rehabilitation process.
Tendinoses
Intense recurrent activity tends to create a chronic tendon disorder, in which the tendon becomes injured, inflamed or ruptured. While this disorder is usually directly related to eccentric muscle movement, the muscle's ability to strengthen and prevent injury through eccentric exercise is excellent. A controlled rehabilitation regime will actually strengthen and repair the tendon. Sufficient evidence supports the idea that tendons, like muscles, can adapt well to physical stress and eccentric loads.
It has been concluded that high-strength tendon muscles that are sent in controlled environments are required for optimal tendon adaptation. While eccentric stress is related to injury, high-style eccentric exercises are required to maximize recovery.
Chronic Patellar tendonitis
Source of the article : Wikipedia
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