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Strength is about opportunity, not about sets and reps

If you are in pain, chances are that someone at some point has told you that a muscle is weak. You follow their strengthening advice, but what happens? That knee still hurts (or whatever it might be).

What happens is that, yes, you strengthened your glutes for example, but if you're honest - nothing has changed. Nothing has changed because strength is about opportunity, not about how many sets and reps you do.

Here I want to bring some clarity to that. I'll talk about anatomy and it might get a bit detailed at times, but I have done my best to make it easy to digest.

So, the theme of this article is this: If there's no opportunity for something to be strong, there won't be strength. What do I mean by that?

What is strength?

If we ask Google, then strength is "the capacity of an object or substance to withstand great force or pressure." If we look at this short definition a little closer, we can already begin to understand why a muscle might not be helping you (according to your experts...).

Let's break it down:


How much load can your muscle take? If the load exceeds the muscle's capacity, things start to break down and it can no longer support you in the movement you're trying to do.

Capacity however builds as a result of adaptation:

We all know that if you train a muscle it will get stronger and bigger. Our body is really good at adapting to whatever you throw at it. Lifting weights is a challenge that your body responds to by building more muscle.

If a muscle is "weak", the capacity of a muscle to withstand a given force isn't great enough to do so. This is why your healthcare professional or coach has told you that you need to strengthen muscle X...

But the question we need to ask is this: Why doesn't it have a natural capacity? Walking the dog is a pretty natural task. Why does the knee hurt? Why is there no capacity for that?

Withstand great force

Withstanding means that there has to be a challenge. If I push you, you can withstand it or I can overpower you. If over time we gradually increase the force that is exerted on your body, your body will adapt to it - your capacity increases as a result of adaptation. This is what training of any kind is founded on (also mental training by the way).

To recap:

Exerted force = requirement of muscle to respond = adaptation = increased strength/capacity

When someone tells you your muscle is weak, what they want is for you to increase strength. That's a no-brainer. But if we approach it from the other direction we can start asking really interesting questions:

We can also say: Capacity is the result of an adaptation to forces that a muscle has to withstand.

So...if there is force that it has to withstand, it will adapt. But no force? nothing to respond to. Nothing to adapt to. No capacity. No strength... what they sell you as "weakness".

So if your muscle is "weak", you should ask: why the hell is there no force that it has to withstand? Why is there nothing that it has to adapt to? So that it can be naturally strong?

We need to look at joint and muscle architecture to answer that question.

How is force exerted on a muscle? - Anatomy 101

Any given joint is surrounded by muscles. Let's take the glute for example (We'll only look at gluteus maximus here). The gluteus surrounds the hip joint.

A joint is the space where bones meet. For the hip, this is where the pelvis and the femur meet. This is often a revelation for many people: the pelvis is not the hip! The hip is where the pelvis articulates with the leg (femur).

The hip can move in 3 dimensions:

It can flex and extend - close and open the front of the hip:

hip flexion extension

It can adduct and abduct: close and open the space on the inside of the leg (groin)

hip adduction abduction

It can internally and externally rotate - well, there's rotation between the leg and the pelvis :)

hip rotation

This is important to consider when we come back our friend the glute:

The glute wraps around the back and the side of the hip joint - it attaches to the femur and the pelvis - kind of like the red shape that I have tried to overlay here. Google it if you want a more accurate view :)


If I want to exert force on the glute - so that it can withstand and adapt - I therefore need to do something to it. I need hip movement.

Let's have a look at what happens to the glute when we move the hip:

Note: I will only focus on the sagittal plane (flexion and extension) here, but the same applies for the other two planes.

glute activation

When we extend the joint, this happens:

The front of the hip opens while the back of the hip closes.

For the glute on the back this means that its tissues shorten, as indicated by the green arrows coming together. I hope you can also see how the red glute shape changes and becomes more "compact". This is what we all know as the muscle contracting.

glute activation

When we flex the hip instead - closing the front, opening the back - the opposite happens: the glute tissues lengthen. Look how big and juicy that glute shape becomes.

So we can see from this: A change in the joint leads to a change in the tissue. If we want a stimulus in the tissue so that it gets the chance to adapt and to be strong, we therefore need: joint motion.

Even though I might be jumping ahead a little, this is what's missing if your glute has been labelled as 'weak'.

First of all, most people lack true hip extension, so the glute won't get the chance to fully shorten (most people's back extend instead of the hip. And many people's backs hurt :) )

But more importantly, the glute in many people also does not get the chance to lengthen and load properly, which is quite a big deal:

Muscles lengthen before they contract

This is another one of the big rules of Anatomy in Motion and it basically means that in order for a muscle to truly kick in (shorten), it needs the ability to lengthen first. Why?

If you want to shoot a rubber band across the room from the tip of your finger, you need to stretch it first. This is what gives it energy to fly across the room.

Muscle spindles in the muscle sense a stretch and they reflexively contract. This happens when the joint is moving into a position where the tissues lengthen so that the glute suddenly has to control the length that is going through it. The response is a contraction (and hip extension).

So simply squeezing your glute is not good enough.

If you are constantly squeezing your glutes tight, how much room for contraction do you have? Where could you get more space to contract the glute from? From a lengthened state!

If someone wants to train their biceps, they wouldn't just lift a dumbell from 90 degrees up to the shoulder and back to 90. In order for the muscle to get the most stimulus (and adaptation), bodybuilders take that dumbell all the way down (and maybe add some rotation to get even more out of it).

The muscle needs to be taken through a range from long to short if you want it to reach its full potential and become "strong". But this can only happen when the joint is able to move!

This should happen in every step you take. This is not a gym thing, not a glute bridge (I hope you can see the limitation for this one), this is human walking gait.

If your glute has been deemed weak, you don't need to ask which exercise gives you more booty burn, but: is this muscle being challenged by virtue of the hip moving?

And then we right away have to look at the rest of the body:

The hip is made up of the pelvis and the femur.

The femur goes down to the knee.

At the knee there's the tiba (shin).

The tibia connects the ankle to the foot.

In the foot there are 26 bones.

If your foot is not moving, your hip won't either. Pronation is critical if you want your glute to lengthen and to have that stretch reflex so that it contracts the hip into hip extension. Without pronation, you won't have that. More on that another time...

Coming round to the title of this article: If a joint is not moving, the tissue around that joint will not get any stimulus. Without stimulus there is no adaptation and without adaptation there is won't be "capacity to withstand force". Stimulus should be there, but it won't if something isn't moving. So muscle strength is not about sets and reps. It's about the opportunity that a muscle gets to be strong.


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