NEW WORKOUT, NEW CLASS IN SESSION: THE BIOLOGY OF THE NERVOUS SYSTEM WHEN LEARNING AN EXERCISE

 

You know that feeling, when you are new to the gym, or it could be your first workout, and you are told to perform an exercises in a particular way? The first few times you try the new movement, everything feels clumsy. 

You overthink each step, your timing is off, and your muscles seem confused. Then a few workouts later, it suddenly clicks. You're smoother, more confident, and more precise.

Who is the real culprit here, playing tricks? The muscles or having to get used to it? Who tells the muscles and how do they learn?

What changed?

Surprise!!! 

It's not just your muscles getting stronger, but your nervous system is learning, adapting, and optimizing the movement.

Think of it as the first day of a new topic your teacher is introducing. You probably will ask a few questions after class, go online or to the library to check it out, and possibly after a few lessons, you can get clicking on things.

The process of improving an exercise is largely neurological at the start. Before hypertrophy, there’s neuroplasticity.

Let’s break down the biology behind how your nervous system helps you go from shaky beginner to movement master.

Improvement Starts in the Brain. Not the Muscles

So firstly, your muscles and nervous systems have daily talks on how movements occurs.

When you repeat a movement, whether it's a squat, a push-up, or a deadlift, your nervous system refines the communication pathway between your brain and your muscles. Basically, your nerves and muscles are working on their communication in a particular matter.

This process involves:

- Better signal coordination (sending the right signals, from nerves to muscles)

- Faster motor unit recruitment (Calling of muscles to do the work)

- Stronger muscle fiber activation (muscles getting primed and ready to work)

- Greater movement efficiency

The nervous system is like a coach teaching your muscles how to move together as a team.

Key Players in the Nervous System During Skill Improvement

Motor Cortex

- Controls voluntary movement

- Initially very active while learning a new motion

Cerebellum

- Coordinates movement and balance

- Fine-tunes motor output based on feedback

Basal Ganglia

- Helps with routine movement

- Becomes more active as a skill becomes automatic

The Neurological Phases of Exercise Improvement

Cognitive Phase (Clumsy but Learning)

This is the place where you personal trainer or coach has brought you in for your first session, and your being taught technique. You perform the exercise, but with some rather comedic moments, if we can say that. So what is happening involves:

- High brain involvement, especially the motor cortex, prefrontal cortex, and cerebellum

- Movements feel awkward and slow

- You have to consciously think through each part of the motion

The nervous system is building a new motor program, like installing a new app.

Associative Phase (Refining the Signals)

A few sessions in and possibly some excuses here and there, your muscles finally begin to get a bit of the hang of things. You begin doing a bit more reps than the first time. So now, your nervous system shows:

- Movements become smoother with fewer errors

- Brain activity becomes more efficient

- You're beginning to rely more on subconscious patterns

Your neurons are firing more reliably in the correct sequences, and the pathways involved are being myelinated (more on this next).

Autonomous Phase (Movement Feels Natural)

At this point, you are getting compliments from your trainer or coach and you are possibly even mentoring some new people coming into the gym, plus posting on social media. So now, your nervous system, graduates, from it's course, and has a new skill, which can look like:

- The movement becomes automatic

- Less cognitive effort is required

- Neural circuits are now well established and energy-efficient

This is when you experience flow, the nervous system has optimized the movement.

It’s not just practice that makes perfect, it’s your nervous system becoming more efficient with every rep.

What’s Actually Changing? (The Science of Neuroplasticity)

When you repeat a movement, your nervous system doesn’t just remember, it physically changes:

Synaptic Strengthening

- Neurons that fire together wire together

- Repeated signals strengthen the connection between neurons involved in that movement

Myelination

- Repeated movement leads to increased myelin, which is an insulating layer around nerves

- Myelinated neurons transmit signals faster and more efficiently

Motor Unit Synchronization

- The brain learns to recruit groups of muscle fibers at the same time

- This leads to stronger, smoother, and more controlled movements

Improvement isn't just about power, it’s about precision and pattern refinement

Neural Adaptations Before Physical Ones

During the first 2–4 weeks of learning a new movement or exercise, most of your progress is neurological, not muscular.

You might notice:

- Increased strength without size

- Better balance or stability

- Less hesitation and smoother coordination

That’s the nervous system doing its job.

Views from the Biolab desk: Why You Should Care

Understanding this can change how you train:

- Don’t expect gains to come only from muscles, movement quality is a neurological achievement

- Repeating a movement well is better than doing it more, quality reps help build better brain-body pathways

- Skill and coordination can be improved even when you're not at max physical effort

Tip: Even visualizing a movement has been shown to activate the nervous system and improve motor learning. Your brain learns by watching and doing.

Recap: How the Nervous System Improves Exercise

Biological Change	Effect on Performance
Motor cortex learning	Faster, more accurate movement commands
Synaptic strengthening	More consistent motor control
Myelination	Faster signal transmission
Motor unit synchronization	Greater force and efficiency

Have more you want us to cover on this or something you encountered close to this? Let us know in the comments.