How to Perform Isolation Exercise for Strength

Set the Scene

We’ve all seen it. The latest fitness fad either coming from the internet or your local trainer that is spouting off something along the lines of, “If you turn your grip inwards by 3.438792 degrees and use the rope handle (only holding one end) whilst you align yourself with the constellation of the stars, then you’ll maximise the activation of your upper ubulis muscle”.

No?

Not seen that? Okay. Well have you ever wandered over to the cable machine and seen the seemingly endless supply of attachments that seems to come along with it. The dozens of prongs, bars and straps that ends up with you wondering whether you’ve walked on to the set of the latest “50 Shades of Grey” film.

WHAT?

Learn the topic.

First of all, what is an isolation exercise?

An isolation exercise can be defined as an exercise in which only one joint is moving under load.

*There is usually a little confusion here, with many people being told that isolation exercise trains only one muscle. Although it may sound like I’m being pedantic, it’s important to note that this is physiologically impossible. Bear with me…

Seven Seas Principle – There’s Only One Muscle

This sounds like a bit of pseudo-science, but it’s actually cold hard fact. And makes complete sense when you think it through.

On good old Planet Earth, we have 4 Oceans from the Artic, Atlantic, Indian and Pacific, but technically, when looking at the Earth at a whole, there is only one ocean. We have placed a name on them and separated them with imaginary lines on the map.

No ocean exists in isolation and they all flow into one another.

Muscles and the human body are exactly the same.

Over the years we have learned to look at muscles in a very isolated fashion. The biceps flexes the elbow. The quadriceps extend the knee.

This was inspired in part, from the early work of the great Leonardo Da Vinci, followed by the father of Modern Anatomy Andreus Vesalius, with their work still influencing our understanding of the body to this day (3). Dissection and dividing the body into segments makes complete sense. They are all architecturally unique and all possess different functions.

However.

They don’t truly ACT in isolation. Just because we drew some lines and divided muscles up with different names and properties, doesn’t mean our bodies all of a sudden said, “Yeah that’s fine bro. I won’t use my gastrocnemius to help on a leg curl because technogym says that only your hamstrings are allowed on that one”.

Pre-Programmed Motion

In fact, recent research suggests that we may have pre-programmed motor patterns (also known as muscle synergies) that stem from our evolution, in that muscles will naturally work together along a kinetic chain to make our movement more efficient (5). So I’m sorry Mr. Bodybuilder Man, but you can’t peak one singular head of your bicep.

What you can do however…is bias one area or part to work a little harder over the other.


Now I know that sounds like I’m being incredibly pedantic, but it’s important to be clear on certain topics. As the well known game of Chinese Whispers goes, a very small piece of misunderstanding can rapidly breed a culture of misinformation.

WHY?

Learn the science and theory.

Isolation Exercise vs. Compound

Where a compound exercise involves more than one joint moving in sequencing, this typically involves a few differences:

  • One joint = less muscle being recruited.
  • Less Muscle = less weight lifted.
  • Less weight lifted = lower systemic metabolic and mechanical demand (i.e. less overall stress to the system).

So, what are some examples:

COMPOUND EXERCISE

ISOLATION EXERCISE

 Bench Press

Dumbbell Flys + Tricep Pressdown

Squat

Leg Extension + Cable Abductions

Bent Over Row

Straight Arm Pulldown + Hammer Curls

Is one better than the other?

Yes. Compound movements.

That’s it. Thanks for joining us.

Isolation! Huh! Yeeaah! What is it good for?! Absolutely Nothing

I’m only kidding, well kind of anyway. As with everything in exercise it’s a matter of context. Sometimes, isolation exercise is more important and more beneficial than selecting compound movements. Below are just a few reasons why you might prefer performing isolation exercise, instead of compound:

  • Bringing up a Lagging body part:

Whether this is from the body sculpt crowd aiming to developing a specific head of a muscle, right through to those of us looking to build maximal strength, you may be significantly weak in one area, that is limiting your overall strength. And unfortunately, the answer can’t always be: “Do more squats”. As mentioned above, compound movements induce significantly higher demand to the system, meaning they are much harder to recover from. So, when you’re done with your squats, jumping onto the leg extension or another exercise that places emphasis on your quadriceps is a great way to bring up your meaty (or not so meaty) thighs.

  • Correct Muscle Imbalances:

In line with the above point, it might be that you don’t have an inherent weakness in an area, rather just one side is weaker than the other. It’s more or less impossible to be perfectly symmetrical. Whether it’s the way you hold yourself when standing/sitting or if you’re suffered an injury, gone through surgery etc. one side of the body may be stronger than the other.

Therefore, you can perform an extra bit of isolation work on the weaker side to help correct it. For example, world class tennis player Nadal is often noted for his significant muscle imbalance between his left “racket” arm and right.

  • Limited Motor Coordination:

No matter how hard you try. You simply can’t crack the squat. It’s a horrendous exercise, that’s stupid, it’s smells funny and you hate it. No one seems to be able to (Start internal link) convince you otherwise. Although you should always learn/strive towards being able to squat regularly (end internal link), in the mean time (whilst you develop your motor limb coordination) you can use isolation exercises to expose the muscles involved to resistance, at higher volumes (i.e. more reps and sets).

There are a fair few more reasons why isolation exercises may be more applicable to you as an individual.


As much as the meat head inside of me would love to scream, “Compound forever” whilst standing over a burning pile of every god damn cable machine in gyms throughout the nation. It’s never that simple. And nor should it be.

After all, a full session of isolation exercises, is still better that no session at all.

Are Isolation Exercises Effective for Strength and Health?

They can be, but I need to stress the following:

Although isolation exercises may be more applicable now, you should always strive towards a compound version.

As you may have read about previously, there is a huge aspect of strength that is governed by aspects outside of the realm of muscles. In fact, more recent research has estimated that only around 30% of your overall strength is determined by muscular properties (4). The rest come from neurological factors, connective tissue strength, skill etc…these are the governing principles of relative strength. And unfortunately, the current prescription of isolation exercises only satisfies the following:

PRINCIPLE OF STRENGTH

ISOLATION EXERCISE

COMPOUND EXERCISE

Muscle Size

✔

✔

Intra-muscular Coordination

✔

✔

Inter-muscular Coordination

✔

Motor/Movement Skill

✔

So…how do we overcome that, and at least try and make isolation exercises more effective and receive a greater carryover to our health, longevity and superhuman strength?

That’s easy. Train the muscles…the way they want to be trained.

When referring to isolation exercises, we are purely talking about the 2 main benefits above: muscle size and intramuscular coordination.

Although we can improve their ability to be involved in multi-joint movement (as you will see shortly), the only real benefits come in the form of training the muscle itself.

HOW?

Learn the implementation.

To Lift or Not to Lift – Muscles Work in 3s

Muscles can primarily generate 3 different types of action:

  • Eccentric – Lengthening of muscle fibres under tension. I.E. Lowering of weight.
  • Concentric – Shortening of muscle fibres under tension. I.E. Lifting of weight.
  • Isometric – Limited change of muscle length under tension. I.E. No change in joint angle.

And although we can effectively train muscles in all 3 ways…each muscle is biased towards and prefers to perform: (a) a specific movement and (b) 1 of the 3 types of action.

How do we know which is which?

This can be a bit complicated and admittedly, may seem a bit nerdy (as with most things I write), but trust me, it’s the difference between wasting your time doing bicep curls or noticing a difference from the extra isolation exercises you’ve been doing to aid your bench press, improve your knee pain etc.

I’m going to break down two different scenarios…

#1 Postural Health

You Can Tell by the Way I Use My Walk…

I know…I’ve used that line before, but it’s important.

As I have continued to read and learn, I’ve noticed one thing about movement.

Almost all movement experts have different methods/techniques of dealing with movement dysfunction. Some prefer manual therapy techniques, others prefer rolling around on balls, spikes, with rubber bands (referring back to the 50 Shades of Grey scenario earlier) others prefer neurokinetic therapy…regardless of their method of treatment, almost all of them acknowledge one thing.

Developmental anatomy and physiology (i.e. from fetus to birth to adulthood) starts with learning how to breathe effectively and builds and builds and builds us up to being able to walk.


Amongst several other movements such as the squat, hinge etc. that many people (myself included) state to be primal, natural movement patterns…are nothing on human locomotion itself, which manifests itself in our gait cycle (walking).


So, if you’re looking to utilise exercise purely to build postural strength, health of your joints etc. then you should look to how muscles work when walking…and train them accordingly.  Now before we go any further…

This IS NOT a comprehensive assessment/analysis of the human gait cycle (that sh*t nearly blew my head off and continues to baffle myself and experts around the world as it is), it is however a simple tip on how to improve the effectiveness of your isolation exercises based on SOME of the aspects of walking that we see day to day.

Let’s take a look at a couple of examples:

  • Quadriceps – When walking, they do aid in producing force and help propel you forward. However, they have a more important role in resisting your knee bending and stabilising the joint. Rather than forcefully straightening against the load of gravity. In fact, the only time your quadriceps really shorten is during the swing phase, when you reach your leg forward.

Preferred Actions – Eccentric then isometric.

  • Gluteus Maximus – Same as before. The glutes obviously aid in all aspects of locomotion. However, they primarily decelerate the limb before the heel touches the ground and then forcefully extend the hip

Preferred Actions – Eccentric then Concentric

  • Glute Minimus, Medius and Tensor Fascia Lata – Isometrically contract to maintain the stability within the pelvis during the support phase (i.e. when you’re stood on one leg).

Preferred Actions – Eccentric then Isometric.

  • Hamstrings – The hamstrings resist forward translation of the tibia (i.e. stop your knee slipping apart and your shin travelling forward) at the knee, and then forcefully extends the hip when propelling you forward.

Preferred Actions – Knee = Eccentric, Hip = Concentric.

*Anderson & Pandy (1).

So, as you can see there…simply performing the typical, 3 sets of 10 = concentric (roughly 1-2 second tempo) followed by eccentric (similar speed)…isn’t half as effective as biasing the exercise towards the muscles preferred action.

#2 Lift, Lift, Lift as Fast as You Can…

…You can’t catch me I’m the gingerbread man (Only Shrek fans will get this reference).

Now, this is where it comes down to individual weaknesses, techniques employed during your lift and therefore, what muscles should be trained. It’s important to assess your own technique, determine where you are at your weakest and use isolation exercise accordingly. 

For example, let’s say you stand wider than shoulder width with your feet pointing outwards. You will typically use more adductors than you would using a narrower stance (2). Then let’s say you struggle with control during the descent of the squat. Then you would be much better using exercises that focus on isometric/eccentric strength of your adductors and glutes, as oppose to smashing lots of leg extensions.


Summary

  • Isolation doesn’t truly exist in the body. It’s fine to use the term, but don’t be confused or led to believe you can truly isolate an individual muscle. We are designed…they are designed to work in sequential movement.
  • Biasing a muscle through isolation exercise is possible. It’s much better to think of isolation exercise as isolating a joint rather than muscle.
  • Isolation exercise is useful to bring up a lagging body part, correct muscular imbalances or to use to develop strength when you have limited motor control in a loaded movement.
  • I would recommend to prescribe isolation exercise for health, based off how muscles act in the typical gait cycle (provided you don’t have any pre-existing injuries and aren’t focusing purely on building strength in a lift).
  • If you are using isolation exercise to build strength in a lift, then isolate (see what I did there) your weak point and what muscles are actively involved in your specific technique.

Reference List

  1. Anderson, F. C., & Pandy, M. G. (2003). Individual muscle contributions to support in normal walking. Gait & posture17(2), 159-169
  2. Clark, D. R., Lambert, M. I., & Hunter, A. M. (2012). Muscle activation in the loaded free barbell squat: a brief review. The Journal of Strength & Conditioning Research26(4), 1169-1178
  3. Ganseman, Y., & Broos, P. (2008). Leonardo da Vinci and Andreas Vesalius; the shoulder girdle and the spine, a comparison. Acta Chirurgica Belgica108(4), 477-483.
  4. Jenkins, N. D., Miramonti, A. A., Hill, E. C., Smith, C. M., Cochrane-Snyman, K. C., Housh, T. J., & Cramer, J. T. (2017). Greater neural adaptations following high-vs. low-load resistance training. Frontiers in physiology8, 331.
  5. Ting, L. H., & McKay, J. L. (2007). Neuromechanics of muscle synergies for posture and movement. Current opinion in neurobiology17(6), 622-628

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Jon Mallon
 

Jon Mallon has spent every waking moment developing his understanding of the body’s capabilities. He has an undying passion for all things strength, with his extensive knowledge from coaching hundreds of clients, to his 1st Class BSc Sports Science and MSc Strength and Conditioning, paving the way to deliver results directly to you. He has been a strength and conditioning coach for a variety of sports from amateur boxing to professional rugby, providing him with the art of coaching required to deliver the science of training. Jon's current areas of focus involve comprehensive postural analysis, neurological strength and evolutionary biology.

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