Q & A: Eccentric Loading.

My trainer mentioned something about eccentric exercises, but I didn't quite understand what he was talking about. What does eccentric mean and why is it important to incorporate this into my routine?

This is a great question. I'll spare you the soap box routine about muscular balance, postural adaptations, learning to use your body efficiently etc etc.. here, but uh, keep that in mind as you read through this :)

There are three types of muscle contractions:

• Concentric: The external load placed on a muscle (i.e. dumbbell in a bicep curl) is overcome by the muscle fibers sliding over one another and thus causing the muscle to shorten.


• Eccentric: The external load on a muscle is greater than the internal force being generated (think placing a heavy box down onto a table). This type of a contraction leads to a lengthening of the muscle fibers.


• Isometric: This is when the muscle is neither being lengthened nor shortened, rather it is staying the same length over time.
  

Most exercises have both a concentric and eccentric quality. For example, the upwards motion of a bicep curl produces a concentric contraction while the lowering forces the muscle to provide eccentric control. It mostly depends on which part you emphasize to change your results.

Muscle spans the length of a skeletal bone(s) attaching at two points. The origin and insertion move towards one another to produce a concentric contraction and lengthen away from one another eccentrically. Muscle possesses the highest potential strength at its belly, growing weaker as you move towards its ends.

Most experienced lifters (and their bodies) understand concentric contractions very well. Concentric contractions (muscle shortening) utilizes the belly of the muscle to overcome the force being placed on it.

Exercises which are eccentric in nature, (think negatives) utilize the entirety of the muscle from the origin to the insertion to accomplish the task, thus producing a much more balanced strengthening pattern. This is why eccentric exercises are currently being viewed as being superior strengthening tools in the fitness arena. This is not to say to ban your bicep curls, but rather switch up your focus so that your muscles can achieve the most benefit.

Eccentric exercises are ALSO very functional in nature. The control gained from them is important for ANYTHING requiring control such as descending stairs, downhill walking, throwing, pushing, and reaching.

Control is the result of the surrounding muscles working in harmony. With muscle imbalances, it is difficult to produce controlled movements.

Isometric exercises are great for stabilization around a joint. The static plank is a great example of an isometric exercise where the muscle is neither lengthening nor shortening, forcing all the muscles around the joint to hold on.

Why does it lead to soreness?

Delayed onset muscle soreness (DOMS) is often seen as a result of eccentric loading on a muscle due to the lengthening quality of the action, leading to microtears in the muscle fiber. You are essentially introducing load to an area of the muscle which barely gets much action, therefore, its essentially like starting a new exercise or adding weight and you should expect to feel some soreness.

Want to incorporate this into your routine?

Change the emphasis from the shortening to the lengthening portion of your contraction by performing counts of 2-1-4.

Two seconds to lift, one to hold in the middle or end, four to lower back to the start position.


How do you feel about eccentric exercise? Had you heard of it before now?

QUESTIONS QUESTIONS, Calling all QUESTIONS! Email me at 101exercises (at) gmail or leave it in the comments!