How to Train Your Nervous System Like a NINJA

By on August 23, 2024

Training your muscle will only get you so far. If you want to tap into your true potential, then you need to develop on what actually controls that muscle: the central nervous system.

CNS

All of us have a vague idea that the central nervous system is important for strength and performance, but how many of you actually know what it is, how it works, and how to target it in your training to make it more efficient?

Keep watching and find out why all training, is brain training.

How the Brain Controls Movement

Simply put, your central nervous system refers to your brain and your spinal cord. As well as being responsible for our thoughts, memories, and personality; this is where signals movements originate that are then fed to the peripheral nervous system, allowing for conscious control over your body.

Your muscles are made up of thousands of muscle fibres – tiny muscle cells that can extend and compress together in order to lengthen and shorten the muscle and move the corresponding joints. They can do this because they are made up of tiny myofilaments. These are comprised, in turn, by actin and myosin. You don’t need to know the details, but these proteins essentially “slide” across each other, allowing the muscle cell itself to shorten, as needed. When enough muscle cells shorten, the muscle contracts.

Brain Controls Movement

Note that individual muscle fibres are binary. They either contract, or they do not. They cannot contract slowly and nor can then contract “halfway.”

To give you a rough idea, the bicep contains somewhere between 200,000 to 500,000 muscle fibres.

But, in order to contract those fibres, you first need to send a signal from the brain – your intention to do so. Inside the brain, therefore, is a region known as the “primary motor cortex.” This contains a map of the body, known as the motor homunculus, where each neuron corresponds to areas of the body you may wish to control. When a signal is sent from this part of the brain – an electrical impulse known as an action potential – it results in movement in corresponding part of the body.

Note that each action potential only lasts for around 10-100ms, depending on the muscle in question. So, in order to sustain a longer contraction actually requires the continuous firing of multiple motor neurons.

When you decide to bend your arm, a signal begins life at the corresponding part of the motor cortex and then makes its way down the spinal cord to the neuromuscular junction to act upon – or “innervate” – the muscle in question.

Motor Unit Recruitment

But here’s the key thing to understand about all of this: the signal does NOT cause the entire bicep to move. Nor do signals act upon the hundreds of thousands of muscle fibres.

Muscle Cells

Instead, they act upon motor units. Motor units are groups of muscle fibres within a muscle that are all “innervated” by a single corresponding motor neuron. These aren’t discreet little bundles of fibres but rather interwoven and scattered throughout the muscle, seemingly at random.

However, the motor units ARE organised into smaller and larger groups of muscle fibres. Likewise, some consist of the powerful type 2a and type 2x muscle fibres, whereas others are comprised of the slower but more efficient type 1 fibres.

The number of motor units in a given muscle varies greatly depending on the muscle in question and genetic variability. However, the average bicep will contain somewhere between 300-800 motor units. These being the smallest contractile units of the muscle. While it would be very hard to do, theoretically it could be possible to contract just a single motor unit.

Motor Cortex

The strength of signal sent from the brain will determine how many motor units are recruited. Weaker signals will recruit only a few of the smaller motor units, as these have a lower activation threshold. But as the neural drive (effort) increases and the signal becomes “louder” this will also be enough to activate the larger and more powerful motor neurons and their corresponding motor units. This means that motor units are ALWAYS recruited from the smallest and weakest, first, with stronger and larger units being added as needed. This is Henneman’s Size Principle.

Seeing as action potentials are binary, you might now be wondering how the “volume” of a signal can increase. The answer is rate coding. That is to say that more rapid signals are able to cumulatively stimulate the motor neurons to fire. As effort increases, so does the rate coding.

Where things get really interesting, is in noting that nobody can recruit 100% of the motor units available to them. Untrained athletes, in particular, can recruit anywhere from 30% to 75% of their motor units depending on the muscle in question and individual differences. Trained athletes, however, can recruit anything from 80-95% of the motor units (reference). Take these figures with a grain of salt, however.

As you can see, then, adaptations within the central nervous system are what will lead to massive increases in strength. Before training, you literally have huge motor units capable of amazing strength within your muscles that you can’t access.

This goes a long way to describe noob gains. But it could also mean you are missing out on a lot of potential strength, even after you’ve grown your muscles.

Fascinatingly, we known that cellists, for example, have physically larger areas in their primary motor cortices corresponding to their fingers. Brain plasticity – the ability of the brain to change shape to adapt to the requirements placed on it – ensures that these often-used areas will actually grow and thicken.

The same is very likely true for athletes. As you learn to control more of the muscle, this would likely lead to an increase in grey matter and cortical thickness in that part of the brain. Making your little motor homunculus even more misshapen.

Think of it this way. I can wiggle my ears because I learned the muscle control necessary to do so. Almost everyone can do this as everyone has the necessary muscles. But, through training and a misspent youth, I was able to gain control over those muscles.

The same thing happens over specific motor units throughout your skeletal muscle. You can move your bicep. But you can only move part of it. And thickening the muscle fibre through hypertrophy training won’t change that.

We call this process: “intramuscular coordination.”

Movement Patterns

There’s another side to all of this too: motor patterns and skill acquisition.

Learning new skills does not result in changes to the muscle. All of this resides in the brain and, specifically, the motor cortex.

As you repeat movements over and over, you create connections between different parts of the motor map. Neurons that fire together, wire together; literally reaching out and forming new connections to allow signals to cross from one to the other. Thus, new neural maps are created, corresponding to particular movement patterns, and reaching from the primary motor cortex, to the premotor cortex (which helps to plan and prepare movement), the supplementary motor area (which helps initiate movement sequences and coordinate the two sides of the body), the basal ganglia (which assists with voluntary movement), and the cerebellum (which fine tunes motor actions).

The more you rehearse these movements, the more efficient the pathways become. Repeated firing actually insulates the pathways, causing long-term potentiation – meaning that one neuron in a sequence more readily innervates the next.

Movement Patterns

Pruning occurs – removing unwanted connections.

Take an untrained athlete and ask them to throw a punch and you will see a pattern light up in their brain. This will be a messy, fuzzy pattern, with the signal leaking out into other neighbouring regions of the brain. Accordingly, their whole body will be somewhat tense. They might hold their breath, they might be contracting their bicep, slowing down the movement. Their shoulders will be up and tense.

Even if they know what to do consciously, it will be very hard not to make these mistakes. Because a strong enough signal to throw a punch will light up unwanted areas of the motor cortex.

In a trained athlete, however, the signal will be much more precise and refined. A trained martial artist can throw a powerful punch while keeping the rest of the body entirely relaxed. Breathing completely normally.

The sequence may also be wrong in the untrained individual. Perhaps the hip turns too late, or the body doesn’t turn enough. They have to actively concentrate to get this part right – whereas its so ingrained for the professional as to be “like riding a bike.” Literally, because the movement pattern is learned in just the same way.

Crucially, it’s also possible to include external stimuli in these movement patterns – which helps us to develop reflexive movements. For example, if someone kicks me low, I will use a lower block to stop it without thought, thanks to years of karate.

When you ride a bike, you take into account feedback from your proprioception and equilibrioception – constantly adjusting position to remain balanced.

When you drive, you likely stop at a red light without needing to consciously remember to do so.

Driving Nervous System

These neural pathways are so strong and ingrained in us that in some causes of traumatic brain injury, individuals who have completely lost their memories are still able to play the piano flawlessly.

The premotor cortex plays a particular role in movements guided by external cues, whereas the supplementary motor area plays a larger role in movements drawn from memory.

We call this “intermuscular coordination.”

Training the Nervous System

Okay, so that’s how the central nervous system works and why it is so important for developing strength and coordination.

But how do you go about training it?

Training Motor Unit Recruitment

Well, if you want to improve your intramuscular coordination – your ability to contract more of a single muscle – then you need to practice sending a stronger and stronger neural drive.

This means you need to lift heavy and/or explosively. 80% of your one rep max and above should generally be enough to train you to send the maximum signal from the brain. Some studies suggest as high as 95%.

When you lift lighter, you simply aren’t sending the strongest signal possible – unless you also move highly explosively. This is one reason bodybuilders – who lift for higher rep ranges – will not develop quite as much strength as powerlifters. They simply don’t practice it.

Overcoming Isometrics

Bodybuilding isn’t useless – other very beneficial adaptations occur, such as developing strength endurance and increasing the mind muscle connection between lesser-used muscles.

There is another way to train this max power output, though. And viewers of this channel already know the answer: overcoming isometrics.

That means pushing or pulling against an immovable object; trying to push down a wall or pull apart a thick rope. Bend a piece of iron.

This works so well because it lets you practice sending the maximum signal for motor unit recruitment. Thus, you get better at sending that stronger signal thanks to brain plasticity. Unlike lifting a 1RM, this also allows you to send that maximum signal for longer (the strength curve means that only a small portion of a max lift actually involves maximum strength). And it allows you to do all that without creating as much muscle damage or incurring such a high recovery demand.

I’ve made videos on this in the past, so I won’t go into it into a lot of depth here – but this is one way to train your nervous system specifically. I’d also recommend the channel “NoLimitSquad” for far more detailed instruction on using overcoming isometrics.

Overcoming isometrics can also be used in other ways. For example, it actually encourages “reciprocal inhibition” meaning it can teach you to relax antagonist muscles – increasing movement efficiency, power output, and mobility.
As for training the movement patters, the key is simply to remember that strength is also a skill. And skills are learned through repetition.

Training Movement Patterns

The goal here, then, is to practice movements repetitively without incurring unnecessary fatigue.

This is where greasing the groove comes in very useful. If you want to learn to perform handstands perfectly, for example, you need to put in the reps and the time. Just like learning to play the piano.

The difference is that you don’t have to worry about managing fatigue as much when playing the piano.

But seeing as handstands are more about skill than strength, there’s nothing to stop you from doing one or two handstands and repeatedly doing this throughout the day.

Spacing the sessions out throughout the day also has its advantages. Specifically, it allows you to repeatedly activate the neural pathways while also giving them time to “reset” in between. This is referred to as “spaced learning” and is more often used to refer to things like revising for a test. But the same applies here.

To the extent that, if your workout includes a skill like a handstand, it might make sense to practice it three times throughout your routine – rather than all at once.

Brain Training

The same can go for practicing perfect squat technique using a lightweight. Because you’re reinforcing those movement patterns, you’re going to make the movement stronger and more efficient. When you DO add weight, you will therefore be better at moving it.

Repeating the same movement perfectly, over and over, will help you to refine your technique more and more. And this becomes increasingly important for skills-based moves like calisthenics, parkour, gymnastics, martial arts.

I recommend that everyone try and learn some more advanced skills like this. Simply because the body control and awareness it will give you will bleed into everything else you do. You’ll learn to move without holding your breath, to control your scapula and your pelvis, and so much more.

But there are two more elements to consider.

One is that you don’t only want to rehearse perfect movements. You also need to add variation and unexpected elements. That might mean doing handstands on uneven surfaces.

The reason for this is that it alters the inputs – and it gives you more practice at adjusting the precise movement patterns. As Nicolai Bernstein says – it builds more “robust movement patterns.” This is another concept I like to discuss ad-nauseum but that’s because it’s SO important to remember and so often overlooked.

I recently discussed this on a podcast with Gregory VonLebe Stark – who has an excellent kettlebell channel that I recommend.

I recommend checking out the full video, but here’s a clip that summarises what I’m talking about.

And it’s also important to remember to include the inputs in your practice. If you want to get good at hitting a ball, you need to practice hitting a ball – not just swinging a bat.

“Frying” Your CNS

Finally, I want to briefly touch on recovery and the concept of frying your CNS. This is a big issue for athletes who are worried that overtraining will “burn out” their nervous system, leading to a complete loss of strength.

And this is something that powerlifters typically see if they simply try and increase the weight on their max lifts over a sustained period. Unless they want to see a plateau or regression in strength, they NEED active recovery.

CNS Fatigue

But it’s important to consider the context here: this actually has very little to do with your central nervous system. New research shows that – while you can fatigue the nervous system – it actually recovers within a few hours maximum. This is NOT a chronic issue. We know this from measuring the strength of the signal at the neuromuscular junction. After 30 minutes to a few hours, it’s back to normal. Possibly a few days – it varies depending on the studies. (Reference)

Interestingly, it also seems that longer-duration endurance training is more likely to cause this effect (reference).

So, why does overtraining make you feel weak? Why do you FEEL like your nervous system is spent?

Well, chances are it’s a lot more akin to what we think of as burnout.

Chances are that it has more to do with your autonomic nervous system, rather than your central nervous system.

That is to say that over time, placing too much demand on your nervous system means being in a heightened state of stress for long periods. That, in turn, can have cumulative negative consequences for performance and health. Essentially, chronic stress – a high “allostatic load” – isn’t good for you; and this can lead to disregulation of the HPA axis, neurotransmitter depletion (potentially), insomnia, loss of motivation, and the accumulation of issues such as injuries and low-level infections.

CNS Fried

The truth is it doesn’t really matter what the precise mechanism is: what matters is that you give yourself a break and don’t push yourself continuously.

Can you train yourself to improve your resilience to long-term stress and high-level exertion? Many believe it’s possible. This is one objective of military training and it’s also seen in the likes of the Bulgarian method of training. Here, athletes lift their maximum lifts daily, and reportedly go through a period of immense distress that they refer to as “The Dark Times” before emerging the other side often with immense displays of strength.

I recommend Alexander Bromley’s video on this subject as it relates to CNS fatigue!

In the short-term, CNS fatigue might be a real problem. If you find the fog descending in the latter rounds of a fight, for example, it might be that your CNS truly is fried. The good news is that there is evidence that you can train to improve this capacity, too. As I’ve described before: J C Santana trains his athletes to improve their “psychomotor vigilance.” To do this, he trains them to the point of fatigue and then has them perform tasks that require focus – such as dodging pool noodles.

Chess boxing might offer similar benefits. And again, we see similar “stress inoculation” training used by certain military groups. Whether this kind of training results in more efficient synapses, increased neurotransmitter receptor sites, or some alternative method, the result is the same: we can improve focus and attention under stress and fatigue, through training (studies).

Closing Thoughts

Is this going to drastically change your training?

Well, this time it actually might. I hope, if nothing else, it shows that a brute force approach to training isn’t always the most effective. Sometimes, a little more finesse can have superior results. It should also show that it’s not all about strength. You can move with power and grace and develop the reflexes of a ninja in a manner completely divorced from strength training.

Nervous System

When it does come to strength, remember: strength is a skill. Treat it as such, and you can tap into some huge reserves of power and performance.

About Adam Sinicki

Adam Sinicki, AKA The Bioneer, is a writer, personal trainer, author, entrepreneur, and web developer. I've been writing about health, psychology, and fitness for the past 10+ years and have a fascination with the limits of human performance. When I'm not running my online businesses or training, I love sandwiches, computer games, comics, and hanging out with my family.

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