The Benefits of Eccentric Contractions in Training

Eccentric contractions provide benefits that are missing in many people’s repertoire.  Do you really think about how you lift a weight?  People want to move weights around as fast as possible without yet having learned to control a weight.  What about how you decelerate a weight?  It seems most of what we see these days is a focus on lifting or accelerating weights.

When it comes to training parameters, there are a multitude of possibilities: volume, intensity, rep schemes, you name it.  We also have “as many rounds as possible” and “for time” prescriptions holding us to moving weight around fast.  We forget that

 

if you can first master decelerating weight, you will become better at then accelerating it

 

Tempo prescription is a parameter that is often neglected but can in fact be a powerful tool for hypertrophy, strength, power, as well as (p)rehab. The deceleration portion of your movement, known as the eccentric contraction, can have an effect on fiber-type recruitment, act as a protection mechanism, affect muscle structure and improve motor control. So, just like The Power of Isometric Exercise in Training and Rehab , eccentrics have their time, place and reason to be during your yearly periodization to optimally and progressively overload your neuromuscular system.

 

Eccentrics for hypertrophy

From a mechanical standpoint, the eccentric contraction increases the stress on muscle fibers. It is a type of contraction that reduces the number of motor units recruited which increases mechanical stress imposed on each fiber. This explains why eccentrics have always been associated with muscle damage, a known pathway that has been used for many decades as an effective tool for building muscle mass.  Additionally, the eccentric part of the range of motion increases fast twitch fiber recruitment, and these fibers are more prone to hypertrophy and force production.

Eccentrics have also been proposed to stimulate structural tendon adaptation, essentially hypertrophic change, which can take extended periods of time, even years.  Thus, it is probably wise to include eccentrics regularly within the training regimen to stimulate these kinds of adaptations.

Eccentric contractions also increase cortical stimulation by their greater motor control demand. They require a better coordination and synchronization of different motor units which is associated with better stabilization and allows the use of heavier loads.  This is another factor that leads to greater mechanical stress on muscular tissue.

I’m just going to open a parenthesis on motor control here.  Surely you have seen people who collapse to the bottom of their squat.  I see this a lot in beginners and younger athletes, who could definitely benefit from eccentric contractions.  Anyway, more on that in a later article.

Video 1: Super slow eccentric 10-0-4-0 is a good way to increase time under tension (TUT) and build hypoxia leading to enhanced protein synthesis. Three to four repetitions provide enough TUT to be within the hypertrophy range (40-70 seconds). It is also a tempo that allows you to focus on controlling the weight and improving mind-muscle connection.

 

Eccentrics for strength

Increases in muscle mass and movement control provided by eccentric contractions result in improved potential when it comes to force production. Additionally, as previously mentioned, eccentric contractions facilitate the activation of fast twitch fibers, fibers that are better suited for the job. Of note: the more often you stimulate the fast twitch fibers, the more easily they will be recruited, resulting in greater force production potential.

In addition, by working on the anaerobic pathway, eccentrics build and increase work capacity. Adaptations stimulated by eccentrics allow you to tolerate higher volume.  This will help reduce the accumulation of fatigue into your subsequent strength cycles, allowing you to hit higher volume at higher intensities.

It has been proposed that eccentrics help to reduce the natural protection mechanism involved during a maximal effort. To put it very simply, your body’s priority is always protection.  Golgi Tendon Organs (GTOs) are proprioceptive receptors that provide information regarding changes in tension within the muscle-tendon unit.  GTOs can send signals that inhibit force production to avoid injury to your muscles.  It has been suggested that accentuating the eccentric contraction can down-regulate the activity of GTOs and allow for greater force production.  However, some studies have raised uncertainty about this mechanism.  That said, eccentrics improve muscle-tendon unit coordination, an important factor in load distribution which we will discuss further in the (p)rehab section.

Video 2: Accentued eccentric 2/1 technique (4-0-1-0)- You can overload the eccentric phase by lowering the with one leg and using both legs for the concentric phase, which increases fast twitch fiber recruitment and improves intramuscular coordination in the targeted muscle.

 

Eccentrics for power

The more strength you have the more powerful you will be, right?  Actually, we should say the more powerful you have the potential to be.  At some point in your periodization you will have to transfer the strength quality into velocity.   The deceleration of a weight increases energy storage capacity of the muscle-tendon unit, a quality useful in sports involving changes of direction and jumping actions.  Deceleration also amplifies the efficiency of the stretch reflex, a mechanism implicated in power production.  Remember, if you can first master decelerating weight, you will become better at then accelerating it.

Video 3: Stretch reflex pre-activation 3-2-x-0.  The slow eccentric pre-activates the fast twitch fibers so that they can be stimulated to a greater extend after the abrupt stretch.

 

Eccentrics for (p)rehab

Eccentrics have long been used for rehab and many studies have been conducted to better understand the effects of eccentric contractions, namely for tendon rehab.

As mentioned in the early part of this article, eccentrics have also been proposed to stimulate structural tendon adaptation.  However, this may take extended periods of time, even years, and as such may not be the sole mechanism by which tendon rehab occurring over 12 to 16-week periods provide clinical improvement.

Tendon stiffness is another element that has been attributed to eccentric contractions.  Stiffness results in better absorption and energy storage and release capacity.  Again, it remains difficult to accurately fully understand these mechanisms in healthy and injured tendons.

One thing we can ascertain is that one of the most important components of tendon rehab is muscle-tendon unit coordination.  Tendons greatly enhance mechanical efficiency by storing and releasing energy, but muscles also need to efficiently decelerate loads to offload the tendon.  Eccentrics allow muscles to operate more efficiently at longer lengths, shifting the length-tension curve resulting in an improve capacity to generate force at end ranges.  This deceleration effect is important for both tendon rehab and prehab.

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The greater motor control demand of eccentrics also has a role to play in (p)rehab.  Eccentrics require greater movement preparation and execution which increases motor drive to the involved muscles.  As well, greater voluntary effort is required for a motor task that is more difficult to control.  This makes eccentrics an excellent tool to activate muscles that have been inhibited by pain or previous injury, as well as to improve neuromuscular control for fundamental movements.

Externally paced eccentric training, such as a metronome-paced tempo, is also an effective rehab tool.  Decreased movement variability has been observed in tendinopathy, and aberrant tendon load from altered motor control is thought to lead to load accumulation in a specific region.  Externally paced training has been shown to increase drive to the muscle and restore movement variability.

Video 4: Externally paced squat (4-1-1-1) Adjusting to the external tempo creates some rep-to-rep variability, which is important in addressing cortical inhibition associated with pain and injury.

 

A sure win

The benefits of eccentric contractions for hypertrophy, strength, power and (p)rehab are all connected.  When you plan your yearly training, you should consider eccentrics to first maximize adaptations to build a solid foundation and then maximize their transferability to other mesocycles.  Everything you gain earlier on will have an effect later on: Hypertrophy is the foundation for strength and strength influences power output.

Whether you are rehabbing an injury or preparing your body to best prevent the risk of injury, it is all about increasing resilience and robustness.  Movement variability and strength are important components of resilience, as is the capacity to efficiently decelerate loads for better muscle-tendon unit coordination.

All of these components of injury prevention and performance are addressed with intelligent programming that includes eccentrics, not only as part of the foundation of your training, but as a continued building block for growth.

 

REFERENCES

Fang Y., Siemionow V., Sahgal V., Xiong F., Yue G. H. Greater movement-related cortical potential during human eccentric versus concentric muscle contractions. Journal of Neurophysiology. 2001;86(4):1764–1772.

Bamman M. M., Shipp J. R., Jiang J., et al. Mechanical load increases muscle IGF-I and androgen receptor mRNA concentrations in humans. American Journal of Physiology: Endocrinology and Metabolism. 2001;280(3); E383–E390.

Duchateau, J., & Enoka, R. (2016). Neural control of lengthening contractions. The Journal of Experimental Biology, 219(2), 197-204. doi: 10.1242/jeb.123158

Rio, E., Kidgell, D., Moseley, G., Gaida, J., Docking, S., Purdam, C., & Cook, J. (2015). Tendon neuroplastic training: changing the way we think about tendon rehabilitation: a narrative review. British Journal Of Sports Medicine, 50(4), 209-215. doi: 10.1136/bjsports-2015-095215

 


 


 

Article by: Pierre-Luc Dubé, B.Sc., kinesiologist

Pierre-Luc’s love for performance and athletic development comes from his background as an athlete himself. Holding a bachelor’s degree in kinesiology from Laval University, he works with clients and athletes who aim to reach new performance levels. His approach is centered around the meticulous periodization of training variables to create a more effective progression and greater adaptations.

Co-authored by:
Mai-Linh Dovan M.SC., CAT(C)

 

 

 

Be part of the conversation

  • That’s an excellent article. What do you think about the eccentric contraction during kettlebell swings and other kettlebell ballistics (snatch, clean)? It is not a slow contraction as in an eccentric squat or deadlift, but there is definitely a deceleration going on during the backswing, which strengthens the posterior chain.

    This is as opposed to people just dropping the bar from overhead during olympic lifting or from hip height during powerlifting as one extreme, and super sow lowers on the other extreme.

    Could you please comment on what sort of benefit (in line with this article) such ballistic eccentrics as delivered by Kettlebell training would bestow upon the body.

    Thank you very much
    Kat Tabakova
    Auckland, New Zealand

  • Hi Ekaterina! Thanks for your comment/question. In the case of a kettlebell swing, there is a need to decelerate the kettlebell as it comes back down, which is indeed a strong eccentric contraction. Strictly from a progression standpoint, you will be more efficient at decelerating it if you have previously trained the eccentric portion of the pattern – which in this case is the hip hinge. As for Olympic lifts, in actual weightlifting, once the barbell is up (overhead for a snatch or at the shoulder for a clean), your lift is completed. Likely you will simply drop the barbell. If you are barbell cycling a snatch or clean, like in Crossfit, then yes, you will also have to decelerate that barbell back to the floor to complete your “touch and go” – again, mastering the eccentric pattern is a prereq to this.

    Hope that answers your question 🙂

    Mai

 

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