Concentric vs. Eccentric Movement: What's the Difference?
When you're moving through a strength workout, it can be easy to zone out while completing rep after rep. But as it turns out—whether it's the down and up motion of a squat, or the lower and lift of a Pilates roll-up—each part of the exercise plays a distinct role. So while you absolutely get credit for showing up on your mat (seriously, great job!), understanding the different phases of your exercises can make a huge difference in your progress.
"In an exercise that involves a range of motion—not a static hold like a plank—the muscles undergo a shortening and lengthening phase," says fitness trainer BB Arrington, NASM-CPT. "The shortening phase is called the concentric phase, the lengthening or lowering phase is called the eccentric phase."
To get a better understanding of concentric versus eccentric movement, trainers weigh in on why they matter, plus tips and tricks for making the most of your workouts.
Concentric versus eccentric: What's the difference?
One of the best ways to picture concentric versus eccentric motion is to consider a biceps curl, says Arrington. "Lifting the weight up toward your shoulder is the concentric contraction, and lowering the weight back down to your side is the eccentric contraction."
In the concentric stage, your muscle is shortening, says Danielle Gray, NASM-CPT, and founder of Train Like a Gymnast. Some examples of this motion include pressing yourself off the ground during a pushup, standing up, and extending your arms overhead.
On the flip side, "An eccentric exercise is one that focuses on the lengthening of the target muscle," says Gray. This includes the lowering phase of a pushup, or slowly returning to the ground during a Pilates roll-up.
What are the benefits of concentric movement?
Both concentric and eccentric movements help build muscle and strength. That said, concentric training is most effective at increasing your maximum power output, or the ability to exert more force in a shorter amount of time, says Gray. "It is argued that more power is generated during the concentric lift because you are moving the weight against gravity, instead of controlling its descent with gravity like an eccentric movement."
What about eccentric benefits?
"While most people are focused on the concentric portion of an exercise, you can go the extra mile by being mindful in the eccentric phase and slowing this part down," says Arrington. Continuing with the biceps curl example, you may notice it's much easier to lower the weight than to lift it. "Because this part of the exercise is not as taxing, slowing down the rate at which you lower the weight is a way to increase the level of difficulty without any additional setup."
Eccentric movements are also thought to cause more muscle damage, says Gray, which is necessary for muscle building.
"Some people like to incorporate eccentric-only training," says Arrington, "or finish a set eccentrically, which is where they have a partner help lift the weight up and they lower the weight down with control."
That said, it is important to note that eccentric movements are known to leave you more sore than concentric-focused workouts, says Arrington. "However, don't let the soreness discourage you from making greater use of them in your workouts."
How to optimize concentric and eccentric training.
For any type of resistance training, it's crucial to only lift what you can with correct form. "Oftentimes, I see gym-goers swinging the weights and using momentum so they 'lift more,'" says Gray. "This leads to joints being used incorrectly, which increases their potential for injury. Plus, she adds that lifting with proper form through the full range of motion will result in more even muscle damage and strength gains.
As for eccentric training specifically, it's imperative to engage your muscles as much as possible, says Arrington. "Oftentimes, when performing an eccentric movement, the client will do the minimum work possible to lower the weight, instead of contracting the muscle as much as possible to lower it down slowly and controlled."
And while you can separate concentric and eccentric training for more focused workouts, ultimately, both movements are important to your overall fitness. "In sport or in everyday life, we move in various patterns, lifting, lowering, and holding; from picking up your child (concentric), to lowering them down carefully in the crib (eccentric)," says Arrington. "It's important to give attention to each to build our strongest most capable selves."
Kristine Thomason is the health and fitness director at mindbodygreen. Kristine is a New York University graduate with a degree in journalism and psychology, and also a NASM-certified personal trainer. She has spent her editorial career focused on health and well-being, and formerly worked for Women’s Health and Health. Her byline has also appeared in Men’s Health, Greatist, Refinery29, HGTV, and more. In her current role she oversees, edits, and writes for the health, food, and movement sections of mindbodygreen.