Muscles You Should Exercise, Core

We are excited to bring you this second article about Antagonistic muscles because it deals with your core muscle pairs. Your core muscles (abs) are responsible for more than you may realize, including your posture.  And because most of us store a good deal of body fat in our bellies, our abs are one of the hardest muscle groups to train.

In our last article we focused on explaining the Antagonistic muscle pairs in your upper body (tap Part I to read more). Today we’ll focus on your abs and as you can see, our next article in the series will focus on the muscles of your lower body.

  • Part I – Upper Body
    • Biceps (Bicep Brachii) / Triceps (Triceps Brachii)
    • Chest (Pectoralis Major) / Back (Trapezius)
    • Shoulders (Deltoids) / Back (Latissimus Dorsi)
  • Part II – Core (abs)
    • Abdominals (Rectus Abdominis) / Lower Back (Erector Spinae)
  • Part III – Lower Body

If you create your own workout routines, include exercises for each muscle pair in your workout routine once a week, focusing on flexibility and strength.

The Information contained in this article is from personal experience and is for recreational purposes and should not be taken as expert advice, or for educational or medical reasons.

What are Antagonistic Pairs?

To quickly review what we learned last week, one of the best ways to stay injury free and get a great workout is to be sure you are exercising antagonist muscle pairs. You can think of the antagonists as the opposite muscles, when one muscle contracts, the other relaxes (lengthens).

“Antagonistic muscles are muscles that work in opposition to each other. For example, a person uses certain sets of muscles to open his hand and splay his fingers wide. In order to close the hand and make a fist, however, an antagonistic set of muscles would have to be used. These muscles are important for balance, extending limbs, holding objects aloft, and contracting limbs, among other things.”

∼ wiseGEEK


Your core, or abs, are no different. Your lower back works with your abs – let’s see how.

So looking at the diagram below, let’s focus on the antagonistic pairs for your core. Antagonistic muscles are the muscles that move your bones in one direction and the muscle pair moves it back.

Antagonistic Muscle Pairs - Core

The Major Muscles Antagonistic Pairs of the Core

  •  Abdominals (Rectus Abdominis) / Lower Back (Erector Spinae)

What These Muscle Pairs Do For You
(and why you need them)

  • Abdominals (Rectus Abdominis) / Lower Back (Erector Spinae)

The rectus abdominis (abs) Core - Abdominal Obliques. muscle is a paired muscle running vertically on each side of the anterior wall of the human abdomen. Abs and erector spinae (lower back), Core - Erector spinae muscles. located in the back, next to your spine, are an antagonistic pair.

Standing from a lying position we use our abs, while lying on our back we use our lower back muscle. The lower back muscle is a small and weak muscle not very often used in our everyday life. When you are doing crunches you workout your abs, but your lower back plays the role of antagonist muscle and acts to brake the end of the crunch. That’s why you may experience some back pain after ab exercises. Be cautious to build up the muscles in your lower back without jerking or twisting too abruptly. You may want to consider alternative exercises to crunches. Tap here >> 10 Flat Stomach Alternatives to Crunches << for exercises to try instead of crunches.

And when the rectus abdominis is well-trained, you can see ‘six pack’ abs that defines a bodybuilder. It’s a difficult muscle to train because most of us store excess fat in our belly. So, we would need to lose the fat there before muscle definition appears.

Agonist Vs. Antagonist

Having two opposing muscle groups is crucial because one can keep the other in check. In a back extension, the abdominals are keeping the lower and middle back muscles in check. If you do a back extension as fast as possible without any weight your spine will move incredibly fast.


The job of the antagonist, the abdominals, is to slow down and stop the spine if it moves too fast or too far backward. It’s important that you don’t upset the balance between agonist and antagonist muscles by constantly working one side and leaving the other side alone. This can create imbalances in posture, which can lead to back problems.


And a word of caution that as you train your abs, be sure to take care of your back. As always, if you are just starting to exercise, it would be wise to seek the advice of your doctor. Additionally, if you have a bad back, or back pain, ask your doctor for exercise recommendations.

Thank you for stopping by today – we hope you found this article informative and useful. Please take a moment to let us know your thoughts about the type of fitness and health related articles you are interested in. We’d love to hear from you!

Wishing you the best of health!

Core Exercises for your consideration…

Want some great exercises to work these agonist/antagonistic muscles? And remember, there are many factors to consider before starting an exercise routine. So, be sure to show your doctor your exercise plan to see if these are right for you.

And Core Motivational Tools for you to consider…

And these books on our affiliate, Amazon, that will explain what core and back muscles to focus on during your next workout (tap the image to browse on Amazon).

Core Exercises - Trainer Edition Core Anatomy of Fitness: Trainer’s Inside Guide
Anatomy of Core Stability Anatomy of Core Stability by Hollis Lance Liebman
Healthy Back Anatomy (Anatomies of)
Back RX: A 15-Minute-a-Day Yoga- and Pilates-Based Program to End Low Back Pain
Inner Body
Health Line
Workouts, Fitness and Nutrition

Please note:  purchases from our Amazon website links help support our site. And the best part is that there is no additional charge for these purchases. We sincerely appreciate your patronage.

Author: Joan

We provide information and motivation focused on the importance of physical activity to our quality of life. It's that important.

6 thoughts

    1. Thanks for stopping by Christy – I always love your visits! Thank you, this was something I wanted to share for awhile now – I know I have to focus on my lower back – like most people, all the attention is to the abs where the fat collects, but the it’s the lower back issues that can land people in bed for a few days. (yes, been there, done that – twice – before I started to exercise) I could never figure out what exactly I did to cause such pain. Now we’re wiser :)
      thanks for visiting!

    1. Thank you AOC! I always enjoy your posts, so I’m happy that I can reciprocate. I do hope you take advantage of some of our exercise pages too. You may already be an avid exerciser, but if not, why not give it a try? I truly believe that exercise is our way to a happier life (at least less painful as we age). Thank you so much for stopping by – I always enjoy your visits! Wishing you and your family the best of health!

      >> Visit America on Coffee for some entertaining posts – I loved watching Ruth Buzzi too!

    1. Thank you Patricia for spending time with us and your note. We are glad you like the link and hope you are staying well.

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