Eccentric vs Concentric – What’s the Difference?

 


eccentric vs concentricEver wonder what the difference is between eccentric vs concentric movements? Can one provide a benefit the other can’t? Should you focus on one over the other? And would it depend on your goals? Below is a short guide on eccentric vs concentric portions of an exercise.

Muscle Misconception

Before diffing into the eccentric vs concentric movements, a misconception first needs to be addressed. Muscles are often categorized as “pushing” (chest, shoulders, triceps) or “pulling” (back, biceps). This is because “pushing” exercises result in separation between you and the weight – like pushing the bar away from you in the bench press. Conversely, “pulling” exercises bring the weight closer to you – like rowing a barbell to your chest.

However, these are misnomers as muscles don’t really “push” nor “pull” – they only contract. When a muscle contracts, it shortens. And when it shortens, your limbs move. Where that muscle is placed on your body is going to determine whether the weight ends up further away from or closer to you. Regardless, your muscles are never “pushing” nor “pulling” – they’re only contracting.

What Is a Concentric Movement?

The easiest way to remember eccentric vs concentric is to actually think of concentric first. The word “concentric” is similar to the word “contract”, and that’s what it’s referring to. Every time a muscle shortens (contracts), this is a concentric movement. So when you curl a weight to your shoulders, that’s the concentric part of the exercise.

Eccentric Is the Opposite of Concentric

If a concentric is when the muscle shortens, then it probably goes without saying that the eccentric is the opposite – or when the muscle lengthens. So if curling the weight to your shoulder was the concentric, lowering it back such that your arms are straight again is the eccentric.

Should You Focus on Eccentric vs Concentric?

A well-rounded workout is going to have you focusing on both eccentric and concentric movements. However, there are times where focusing on one or the other can be beneficial. For example, if maximal power is your goal, doing concentrics as explosively as possible with little-to-no eccentric would be ideal. Examples would include Olympic lifts where you drop the bar back to the floor or plyometrics where you jump onto a box, then step back down.

On the other hand, your muscles are actually much stronger during the eccentric portion of a movement. This is why doing “negatives” (using outside help to get to the fully contracted position, then lowering slow and controlled back to the beginning of the movement) can be so effective at building additional muscle and strength. You just have to watch out when adding negatives to your workout, as they can easily lead to nervous system burnout.

There are virtually limitless ways to program eccentric vs concentric movements using rep speed, cadence, pauses between reps, and more. Of course, what sort of variation you choose is going to depend what you’re training for.

However, if your main training goals are to have a good overall combination of strength, muscular size, and explosive power while not overtraining your CNS, a good approach is to perform your concentric as quickly as possible while still maintaining control. Hold the contracted position for a second, then perform a slower eccentric – say 2-4 seconds. Reset for your next rep, then repeat.

In the end, you don’t need to complicate eccentric vs concentric. Concentric is when your muscles shorten and eccentric is when your muscles lengthen. For most training goals, performing the former fast & explosive while slowing down on the latter will build the physical qualities you’re looking for. However, you can change things up if you need to accomplish something specific.

If you found this article interesting, you should read up about time under tension.