Login | February 19, 2019

Eccentric muscular contractions

PETE GLADDEN
Pete’s World

Published: February 4, 2019

Most people typically associate resistance training with the action that involves muscle shortening…you know, like raising the dumbbell while doing a biceps curl. But that’s only the half of it, because there’s also the action that involves muscle lengthening. And that action can be just as important in the whole muscle building/strength gaining process as the shortening action.

So with that theme in mind let’s begin this conversation with nomenclature and definition, then we’ll get into the whole muscle lengthening thing.

Okay, the muscular actions you typically see being performed in a gym are termed isotonic contractions - those which cause the muscle to change length as it contracts and causes movement of a body part. And these isotonic contractions are of two varieties, concentric (muscle shortening) and eccentric (muscle lengthening).

Now as I said, concentric contractions happen to be the most familiar of the two isotonic muscle contractions, the one we all associate with that dumbbell curl. And this familiarity is likely because these contractions frequently occur in everyday life as well as in athletic/fitness settings.

So in the aforementioned dumbbell curl, the concentric contraction occurs when the elbow moves from a straight to fully flexed position, causing a shortening of the biceps muscle as the weight is raised.

Eccentric contractions, on the other hand, can be described as braking contractions, where the muscle is doing negative work. That’s why gym rats typically call eccentric reps "negatives."

A good example of an exercise employing the muscle-lengthening eccentric contraction is…surprise…also the dumbbell curl, where the elbow moves from a fully flexed to a straightened position as the weight is lowered. Again, the biceps muscle is contracting, but now it’s lengthening.

Now I believe the reason we so universally view the concentric contraction as the end-all-be-all of resistance training is likely because this muscular contraction fits so well within the principle of progressive overload, a principle which states that in order to obtain muscle growth and strength gains, muscles must be forced to adapt to progressively higher levels of tension.

So over the years the concentric contraction (the lifting phase) has come to be known as the superstar in facilitating muscular development. But does it deserve such fame?

In reality both contractions trigger muscle growth, as proven by legions of exercise physiologists. And actually, there’s one school of physiological thought that believes the lesser known eccentric contraction to be the one that deserves a greater share of the kudos.

Knowing this, let’s now take a look at just how to accentuate your resistance workouts by taking advantage of this less familiar of the two isotonic contractions.

You can instantly get more bang out of those isotonic movements by slowing down the eccentric portion. Now there are various tempo (cadence) recommendations for achieving different kinds of results. And in general, the faster the tempo, the more emphasis there is on power development. The slower the tempo, the more emphasis there is on strength development and muscle building. Understanding these subtleties allows you to become more sophisticated with your workout parameters.

Incorporate occasional bouts of pure negative training into your workout routine. This is yet another strategy in strength training which can lead to greater strength gains. Negative training involves using heavier weights than you could typically lift “with good form” concentrically. You’ll either cheat through the concentric portion or have partner assistance, and then concentrate on the eccentric lowering portion with a lowering cadence of two to four seconds per rep.

This negative training strategy also applies to body weight resistance exercises. For example, if you’re not able to perform a pull-up or chin-up, then you could work on the exercise from a negative perspective. In this case use a step to get proper position on the bar, step off, and then slowly lower yourself. Begin with three to four negative reps as your starting point.

Eccentric work can - and will - quickly condition and build muscles because they require more force than concentric work. But keep in mind that negative and cadence training should be undertaken in a slow and progressive manner. Increase intensity and volume over time so the muscles and tendons are able to become stronger and less prone to injury and/or soreness.

So think of your resistance training in terms of both concentric and eccentric contractions. Do that and I guarantee you’ll be breaking down barriers.


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