Mind-muscle connection is commonly thought as one of the MOST important variables in resistance training. But is this true?

Today, I’m going to dissect mind-muscle connection, explain why I think it’s overrated as a concept, and recommend what to focus during training instead.

I asked ChatGPT what mind-muscle connection is, and why it’s important. I like to ask AI models these kinds of questions because I think that its answer represents the most popular answer that people generally subscribe to.

Contraction

To analyze mind-muscle connection, we first need to understand how contraction works.

When muscles contract, they create a force called tension.

Tension refers to the pulling force that’s created within a structure when two ends of that structure are pulled in parallel and opposite directions.

You can think about contraction like you’d think about pulling two ends of a rope apart. Here’s a visual of what tension looks like:

Muscles create tension in the same way that two people pulling a rope apart create tension. In a muscle, tension looks like this:

The green arrows represent the tension force that muscles ultimately create. This is made possible by the white arrows, which represent the direction in which the structures within the muscle pull each other.

Muscle tension is therefore what we call contraction, and vice versa. Muscle tension is not “good” or “bad”, but is rather just a description of the force that muscles create.

Tension in any object requires two opposing forces, as we already mentioned.

In the context of human anatomy, tension in a muscle can only be created when that muscle has a force that it needs to respond to.

“Intentional” Contraction

“Intentional” contraction refers to what ChatGPT describes as mind-muscle connection.

To illustrate this, we can use the example of “flexing” muscles.

Hold your arm up and out to your side, like you’re “making a muscle” to show off your arms, like this:

Notice what happens when you “flex” your arms - you’ll feel sensation all through your biceps, but you’ll also feel sensation through the triceps, forearms, and shoulders.

To accompany this sensation, you’ll also notice that all these muscles feel somewhat “hard”, meaning that all of the muscles along the upper arm are contracting together.

Now let’s do something else: instead of “making a muscle”, put your hand up against the bottom of a table (or something similar), and pull your hand upward against the table like you’re doing a biceps curl.

When you curl up against the table, don’t attempt to “make a muscle” with your arms like you did before. Just raise up against the table like you’re going to try to lift it upward.

Notice the difference in the feeling that you get when you don’t have any intent to “squeeze” everything in your arm.

Feel your biceps and your triceps now, and note the fact that your triceps feel a lot less “hard” compared to the initial flexing.

Why might that be?

Contraction = Response

What do we learn from the above demonstration?

Contraction is just a response governed by the brain.

When you didn’t have anything to "curl” against - where you were making a muscle - both the biceps and triceps had to contract for either one to create tension.

But when you put your hand underneath a table, your triceps relax a bit, and your biceps take over the contraction.

In the first example, you didn’t have any external force against which to contract. You weren’t resisting anything in the external world, other than the force of gravity attempting to pull your arm downward.

But in the second example, you had an object that you were resisting - much like you would in the gym while doing an exercise.

In the first scenario, you HAD to create a contraction in your triceps to be able to create a contraction in your biceps. This is because the biceps needed something to pull against to contract with high fore.

But in the second scenario, your brain didn’t need to contract your triceps (relatively) at al because the biceps could act against an external resistance to create tension.

So what’s the point here? And how does this relate to mind-muscle connection?

The Problem with Mind-Muscle Connection

Any time we consciously attempt to create contraction - with or without significant external resistance - we need to create force against ourselves to create tension in a muscle.

In the first scenario, where we were just focused on “flexing” our biceps, we needed to create resistance against ourselves.

But in the second scenario, where we were just focused on resisting against the table, the table provided a force against which we could contract.

The purpose of using weights is the same as using the table - to train muscles with external resistance.

Suppose we are consciously attempting to create contraction at the same time that we are acting against an external resistance. In that case, we are both resisting an external force AND creating internal forces directly opposite the motions we are attempting to create.

This kind of conscious “squeezing'“ of muscles often results in heightened sensation in and around the target muscle because we are attempting to create two opposing motions at the same time.

For example, if I’m doing a DB curl but I am also attempting to squeeze my biceps as much as possible, I have to resist the force of the DB in addition to the force I’m creating through my triceps.

This results in a downregulation of tension in the biceps when performing the curl because my brain now has to divide attention between doing the curl and contracting my triceps.

This “intentional contraction” is thus a strategy that heightens awareness of the working muscles, but not in any way that is productive to the goal of the exercise.

If my goal is to train my biceps, I don’t want to create a situation wherein I’m fighting the contraction of my triceps simultaneously. This ultimately defeats the purpose of using a dumbbell to do a curl.

So, rather than consciously contract our muscles during exercise, I propose that we treat muscles unconsciously and that we pay attention to moving our bones against resistance, rather than attempting to control muscle against itself.

A Perspective Shift

In the context of resistance training, contraction should be conceptualized as a response to external forces based on the position of our bones.

In other words, if I’m performing a DB curl, my intent should be to think about what the resistance of the DB curl is doing to me and how I need to move my bones against that resistance to train the biceps.

I often find that the people who are the most focused on intentionally contracting muscles are the people who 1) struggle to learn exercises the most and 2) have difficulty progressing in load and reps over time.

When we intentionally attempt to create contraction - rather than act against an external resistance - our brain becomes caught between a rock and a hard place. Our brain has to manage the complexity of attempting to create a contraction in two opposing directions.

You also often see these people “shaking” during very basic movements -which again is a representation of how the brain is trying to get the individual to “let go” of the intent to intentionally contract.

If you’re not bought into this perspective shift just yet, let me use another example to hopefully convince you, using the DB curl as an example again.

Recall that intentional contraction is contraction which our brains create against ourselves.

If I’m intentionally contracting during a curl, the triceps are resisting the biceps to some extent.

But take this to the extreme…

If you were squeezing your arm hard enough, your arm actually wouldn’t be able to move. Instead of your elbow bending, the triceps and biceps would both be resisting each other maximally in an isometric contraction at the bottom of the movement.

The ONLY way for you to perform the curl is if you “let go” of contracting the triceps so that you can resist the DB pushing your hand toward the floor.

If you squeeze hard enough, the DB - and your forearm - will not be able to move upward toward the ceiling. You’ll just forever be stuck between this muscular “rock and a hard place”, and you won’t be able to resist the DB’s force against you at all.

What Should I Do Instead?

I propose that, during resistance training, we concentrate on two things:

1. Motion of bones

2. External resistance

It sounds silly, but we don’t actually control the motion of muscle, we only control the motion of bones.

The position and direction of motion of our bones and their relationship to the resistance of the exercise is ultimately what makes every exercise unique.

I encourage the people I’m coaching to “resist the resistance”, knowing that if they’re acting against an external force, the internal forces of the exercise will take care of the muscle I’m trying to recruit during that exercise.

Understanding how to train each muscle group is ultimately just a product of understanding where muscles attach to the body and using basic physics to load those muscles so that they can respond.