Adaptations from Eccentric Contractions
In the previous topic, you learned that each muscle is capable of three contraction types: concentric, eccentric, and isometric. Each contraction type has specific adaptations to render its own set of adaptations to achieve an athlete’s specific set of goals. This week we focus on the eccentric contraction, and its many adaptations. This is one episode that I recommend you pay close attention to because there are many adaptations that are useful to almost any athlete.
Menu:
- Description of the Eccentric Contraction
- Specificities of the Eccentric Contraction to Yield Specific Adaptations
- Examples of Eccentric Focused Movements
Description of the Eccentric Contraction:
Previously we covered the topic of concentric contraction which is the shortening of a muscle. This week, our focus is on the eccentric contraction which is the lengthening of a muscle allowing for movement in the opposite direction. An example of an eccentric contraction is the biceps brachii lengthening after a biceps curl once again bringing the muscles to a lengthened position moving the lower arm away from the upper arm.
Specificities of the Eccentric Contraction to Yield Specific Adaptations
During eccentric contractions, there are several adaptations that take place. I believe that eccentric contractions are one of the most underutilized stimuli in most strength training rooms world-wide. Here are the adaptations:
- Reduction in Spinal Inhibition
- Increases in motor unit recruitment
- Strengthened collagen
- Strengthened Titin molecules
Eccentric contractions experience immense amounts of force because they are also forming myosin and actin cross bridges and less detachments if performed slowly making this contraction equally capable of force production in regards to active force production with muscle fibers. Yet, eccentric contractions come with passive force production from elements in the body that resist stretch like collagen and titin molecules. The high forces cause an increase in motor unit recruitment, which is one of the main adaptations required for strength.
Spinal inhibition is caused from the elements in the nervous system designed to alert the body of high forces being experienced. For example, Golgi Tendon Organs that can be found in tendons to prevent tendon ruptures caused by high forces. Over time the body becomes adapted to the high forces of eccentric contractions, and allows more force to be produced without inhibition.
Collagen and Titin are both increased in strength and size from resisting the stretch of muscle fibers. Collagen can be found in tendons and also in the surrounding layers of a muscle and the various components within a muscle. For example, the endomysium is the collagen layer surrounding each muscle fiber. Each muscle fiber can transfer force laterally with possible costameres to the endomysium that will then transfer the force longitudinally to the tendon. If the endomysium is strong, the force will be transferred immediately to the tendon at a higher rate. The same is true with collagen found in the actual tendon. Titin is the biggest protein filament found within muscle fibers, and is responsible for structure and resisting movement. Titin is like a rubber band. The stronger it becomes results in a more massive counter production in force.
Examples of Eccentric Only or Eccentric Focused Exercises:
There are several ways to take advantage of the possible adaptations from Eccentric Contraction Focused exercises. I will show you a closer look at these movements in the video, but here are some examples:
- Flywheel– A flywheel machine is my favorite when it comes to emphasizing the eccentric contraction. This is an article in itself, but don’t worry there is an article soon to come explaining the incredible benefits of flywheel training. The important thing to know is that the flywheel runs off of inertia. The stored energy from the concentric contraction overloads the eccentric contraction leading the incredible results especially with the use of Velocity Based Training.
- Weight Releasers: these are contractions that are added to the barbell allowing extra weight to be lowered, and then at the bottom of the movement the weight releasers kick off allowing the athlete to use less weight during the concentric phase. These allow for a greater focus of high threshold motor units due to the excess force capabilities made possible by the stretch resistant properties within the body (collagen, tendons, Titin, etc).
- Partner Assisted Negatives: an athlete will need 2-3 partners to complete this method. This can be performed with a bench press, deadlift, or squat. The athlete simply lowers the weight controlling the eccentric contraction 3-5 seconds. At the bottom of the movement, the weight is taken by the partners.
I recommend considering 3-6 sets of 1-5 repetitions. If strength is the primary goal, the athlete is better off with lower reps. For hypertrophy, I recommend closer to the 5 repetitions. Eccentric contractions are the most under-utilized method in all of strength and conditioning especially considering the incredible adaptations that are possible. We use GymAware Cloud to monitor the eccentric contraction in terms of time, velocity, power, and force. It’s important to monitor long term progress as well as daily intent.
Go back and read the article on bar velocity for an even better understanding of how to measure each contraction for the desired adaptation to be ensured. When a strength coach understands the speed of contractions along with the various adaptations from the different muscular contractions, most any adaptation is possible. One thing is for sure, you will have an added ability to ensure proper adaptations for individual athletes.
As always, if you have any questions, email me at Travis@GymAware.com.
Watch the video presentation here:
Being a World Champion in powerlifting, Travis competed at a world-class level in Olympic weightlifting and has coached professional Olympic weightlifters alongside Don McCauley and Glenn Pendlay at Team MDUSA. Now Travis coaches the most successful weightlifting team in the USA.
