Are you curious about stabilizer muscles? 

Do you want to know whether stabilizer muscles actually matter, and what role they play in building size and strength?

Then you’ve come to the right place.

In this comprehensive guide, I will teach you everything you need to know about stabilizer muscles, including how to train them for optimal results.


  • Part 1: The Pro-Stabilize Muscle Camp
  • Part 2: The Anti-Stabilizer Muscle Camp
  • Part 3: So, Who's Right? Should You Train The Stabilizing Muscles?
  • Part 4: The Rotator Cuff
  • Part 5: The Lower Trap
  • Part 6: The Long Head Of The Biceps
  • Part 7: Discussion

People in the fitness community love to argue about the role of stabilizing muscles. It is one of those controversial topics like intermittent fasting fasting.

There are two schools of thought on muscles that supposedly help stabilize the body.

Funnily enough, the two schools of thought are about as opposed to each other as die-hard proponents of carnivore and vegan diets!

Do stabilizers actually exist? The answer may surprise you!

Part 1: The Pro-Stabilizer Muscle Camp

On one hand there is the pro-stabilizer muscle camp.

They make the argument that training the smaller stabilizing muscles is key to maximizing progress.

They love nothing more than to talk about how incline dumbbell presses recruit all of the little stabilizing muscles that are neglected with barbell incline presses.

According to this camp, free weights are clearly superior to machines, because machines neglect these smaller supporting muscles.

They say the reason you are so weak when performing free-weight work after using machines for an extended period of time is that you neglected all of the little stabilizers.

Some of the proponents of this line of thought are big into “functional fitness” trends.

Most of the functional fitness methods that are pushed in the fitness community today are about as useful as tits on a bull.

However, some of them, including strongman training and the hanging band method, do have value.

Part 2: The Anti-Stabilizer Muscle Camp

On the other hand there are those who say that the stabilizer muscles theory is a sham!

“Show me a muscle that stabilizes my other muscles – I've never seen one” is a very popular response from members of this school of thought.

Many bodybuilders have accepted this philosophy as the truth.

As long as they can feel the target muscle working then it doesn't matter if the exercise uses free weights, cables, or machines.

If they can effectively contract their muscles against the resistance and get a great pump then the exercise has value.

IFBB pro Shelby Starnes went so far as to almost exclusively use machine-based exercises in his training for a long period of time when he was still an amateur competitor.

In fact, for a period of time, the only free-weight exercises he was performing were deadlifts and rack deadlifts!

If machine-based training doesn't provide a stimulus for hypertrophy then someone certainly forgot to tell Shelby's muscles.

Part 3: So, Who's Right? Should You Train The Stabilizing Muscles?

This is an fact a rather silly question. I want to make the following as clear as possible:

There is no such thing as stabilizer muscles – only muscles that act as stabilizers!

What do I mean by this? Let's look at some examples.

Part 4: The Rotator Cuff

When performing the bench press the muscles of the rotator cuff (infraspinatus, teres minor, supraspinatus, subscapularis) are responsible for stabilizing the shoulder joint.

They help prevent the shoulder from thrusting out of its socket during the bench press.

Therefore, they serve a stabilization role.

However, when performing seated dumbbell external rotations, the external rotators (infraspinatus, teres minor) no longer serve a stabilization role.

Instead, they become the prime movers of the exercise!

In fact, the internal rotators of the humerus, including the pecs and the lats, now serve a stabilization role.

If you've ever lifted a gallon of milk out of the trunk of your car, or “cleaned” a strongman log up onto your shoulders, then you've experienced first-hand how the external rotators can be the prime movers of a movement.

Let’s look at another, more straightforward example.

Part 5: The Long Head Of The Biceps

When performing the bench press, the long head of the biceps actually plays a rather important role in controlling the positioning of the scapula.

In fact, if an individual slows down at the mid-point of a bench press,

it may actually be a sign that the long head of the biceps is too weak for what the individual can bench press!

The brain will send signals to shut down the prime movers, including the pecs, anterior delts, and triceps, so as to prevent injury.

The long head of the biceps clearly plays a stabilization role in the bench press!

However, when performing supinated grip sternum chin ups, the long head of the biceps is actually considered a prime mover of the movement.

To recap, in one compound exercise, the long head of the biceps plays a stabilization role.

In another, it is one of the prime movers.

Let's take a look at one more example for good measure example.

Part 6: The Lower Traps

In some instances, a muscle can function as a prime mover, as well as being a muscle that stabilizes. Consider the role of the lower trap during the overhead press.

The low trap plays a critical role in maintaining optimal positioning of the shoulder in the shoulder socket.

In fact, it retracts, depresses, and posteriorly tilts the scapula.

However, it can also be considered one of the prime movers of the movement as it plays a critical role in achieving upward rotation of the scapula that is essential for achieving full shoulder flexion.

Part 7: Discussion

To review, there are two main opposing schools of thought when it comes to muscles that play a stabilizing role:

There are those who are in favor of training them, and those who feel such time is wasted.

The problem with both schools of thought is that the stabilizers do not actually exist in reality as such!

As you can see, it is critical to use the proper terminology here.

Failure to do so can instill incorrect biases and negatively impact your own program design.

This is not to say that machine exercises are inherently as effective as free weights, or worse, that there is no place for accessory work in proper program design.

Nothing could be further from the truth!

To be clear:

I am not against accessory and remedial exercises!

As they say, a chain is only as strong as the weakest link.

If an individual muscle is too weak then it will often be overpowered by other muscle groups in compound movements.

Isolation exercises are necessary in such instances to re-educate the weak muscle before re-incorporating the compound movement.

For example, if your external rotators are so weak that you have to use the pink dumbbells on seated dumbbell external rotations, then targeted isolation work would certainly be warranted to bring this muscle up to par.

One of the keys to being a great coach is the ability to quickly and accurately identify the weak links holding back an athlete’s lifts.

This is what makes structural balance testing so valuable!

It allows you to identify the weak links limiting an athlete’s performance and to design training programs to address these weak links as quickly as possible.

Now get back in the gym, train the remedial exercises and whatever weak links you have holding back your performance, and watch your gains take off!