🧠 UNDERSTANDING THE SYMPATHETIC AND PARASYMPATHETIC NERVOUS SYSTEMS
🛡️ A SURVIVAL SYSTEM WE RARELY LEARN TO DRIVE PROPERLY

Evolution has given us a built-in survival system designed to help us recognise danger, respond to threat, and recover when the danger has passed. This system is known as the autonomic nervous system.

It operates largely below conscious awareness, constantly scanning the environment and adjusting our internal state to match what it perceives. When danger is present, it prepares us for action. When safety returns, it shifts the body back into repair and recovery.

Most people involved in martial arts have heard of fight or flight.
Very few truly understand rest and recuperation.

That imbalance alone explains why so many martial artists train hard, recover poorly, feel permanently wired, and eventually stall, break down, or burn out.

The autonomic nervous system has two primary branches that work together.

⚡ The sympathetic nervous system acts as the accelerator.
🛑 The parasympathetic nervous system acts as the brake.

They are not opposing forces in conflict. They are complementary systems designed to be used together. One allows you to move fast, generate force, and survive threat. The other allows you to repair, adapt, and return to baseline.

You need both.
More importantly, you need access to both on demand.

🚦 My EARLY TRAINING AND LIVING ON THE ACCELERATOR

When I first started training in karate, I was surrounded by people working security and door work. The focus in those circles was very clear. Everything revolved around engaging the fight or flight response. We were interested in survival, real-world violence, and how to function under genuine threat.

At that time, everything I understood about the nervous system was essentially the sympathetic side. We talked about adrenaline, aggression, commitment, and pushing through fear. The goal was to be able to switch that state on quickly and operate effectively once it was engaged.

For a long time, I did not even know there was something called the parasympathetic nervous system. There was no concept of a brake pedal. If something hurt, if the body felt run down, the assumption was simple. You were injured. You needed physical therapy. Then you got back to work.

So for years, I kept the accelerator pressed hard.

And to be fair, it worked. In a security setting, the ability to engage fight or flight on demand is essential. You cannot hesitate. You cannot be tentative. You need that sympathetic nervous system response available and reliable.

The problem was not using the system.
The problem was living in it.

By my mid-twenties, after years of constant high arousal and hard martial arts training, the cost started to show. Nothing dramatic. No single catastrophic injury. Just accumulated wear and tear. Constant tightness. Lingering pain. A body that never quite felt settled.

⚡THE SYMPATHETIC NERVOUS SYSTEM - THE ACCELERATOR

The sympathetic nervous system is responsible for what most people recognise as fight or flight.

When it is dominant:

• Heart rate increases

• Blood is shunted to the muscles

• Digestion shuts down

• Peripheral awareness narrows

• Pain perception drops

• Strength and speed increase

This is not a flaw in human design. It is a survival system shaped by evolution.

In full-contact swordplay and martial arts, this system is essential. Without sympathetic activation, you cannot:

• Commit to an entry

• Tolerate impact

• Move explosively

• Act decisively under threat

The mistake many martial artists make is not activating this system.
The mistake is never learning how to disengage it.

🛑 DISCOVERING THE BRAKE PEDAL

The turning point came when I went for a shiatsu treatment. At the time, I was not looking for nervous system education. I simply thought I was injured and needed some form of physical therapy.

What surprised me was the result.

Unlike other treatments I had tried, where you feel looser for an hour and then slide back to where you were, this was different. I had the treatment on a Friday. By the time I reached Monday, my body felt genuinely better. More settled. More coherent.

That experience led me to enrol in a five-year shiatsu training programme. It was there, for the first time, that I encountered the concept of the parasympathetic nervous system.

This was the first time anyone had explained to me that there was a brake pedal.

Everything up to that point had been about learning how to push harder. Now I was being shown how recovery actually works, and why nervous system regulation matters.

The body does not adapt during training.
It adapts during recovery.

Training applies stress.
Recovery produces change.

🛑 THE PARASYMPATHETIC NERVOUS SYSTEM - THE BRAKE

The parasympathetic nervous system governs:

• Recovery

• Tissue repair

• Hormonal balance

• Immune function

• Emotional regulation

This is the physiological state in which adaptation happens.

If you cannot access parasympathetic dominance effectively, your training sessions accumulate stress instead of producing progress. You may still improve for a while, but eventually the system overloads. Performance drops. Injuries linger. Motivation fades. Everything feels harder than it should.

Many martial artists interpret this as a lack of discipline.
It is not.
It is a nervous system literacy problem.

🧭 THE NERVOUS SYSTEM IS INVOLUNTARY, BUT NOT INACCESSIBLE

The sympathetic and parasympathetic systems are part of the autonomic nervous system. This means you do not control them directly in the same way you control a muscle.

You cannot simply decide to relax harder or activate more.

However, involuntary does not mean inaccessible.

You can influence these systems indirectly, and the most reliable gateway is breathing.

🌬️ BREATHING AS THE CONTROL INTERFACE

Breathing sits at a unique crossroads in human physiology. It is:

• Automatic

• Voluntary

• Continuous

This makes it the most effective interface between conscious intent and involuntary nervous system function.

Slow, controlled breathing with extended exhales biases the parasympathetic nervous system.

Short, sharp, forceful breathing biases the sympathetic nervous system.

This is not mystical.
It is mechanical and neurological.

Through breathing, you gain leverage over systems that would otherwise remain out of reach.

🎯 FROM BREATHING TO INTENT

Once breathing patterns are established, intent can ride on top of them. This is where martial training becomes sophisticated.

A trained practitioner can:

• Use breath to downshift after a hard exchange

• Use breath to deliberately raise arousal before entry

• Recover between rounds faster than opponents

• Maintain clarity under pressure instead of spiralling into panic

This is not about being calm all the time.
It is about choosing when to be calm and when to be dangerous.

When I began studying Taiji under Steve Rowe, it gave language and structure to something I had already begun to experience. A central aspect of his teaching was the ability to inject adrenaline deliberately, to tap into the adrenal system on demand rather than being hijacked by it. The older internal training systems may not have used modern neurological terminology, but they were deeply concerned with this same practical problem: how to raise intensity precisely when required, and how to dissolve it just as cleanly once the moment had passed.

That understanding was reinforced through my sword and Taiji training under Scott Rodell . In his teaching, a defining quality of the Jianke (a swordsman) is calm. Not calm as passivity, and not the absence of aggression, but calm as internal stability under pressure. He draws a clear distinction between boldness and calmness. Boldness alone tends to be reactive and repetitive. Calmness allows decisive action without fixation or panic.

Seen through a modern physiological lens, both approaches are pointing toward the same underlying skill. The ability to regulate nervous system arousal rather than be driven by it. Calm, in this sense, is not a mood or a personality trait. It is a trained capacity to remain internally settled while operating at high intensity.

⚔️ WHY THIS MATTERS FOR MARTIAL ARTISTS

At high level full-contact swordplay, the nervous system is almost always the limiting factor.

Not strength.
Not technique.
Not conditioning.

The ability to switch gears, to press the accelerator hard and then apply the brake cleanly, determines:

• Longevity in training

• Quality of decision-making

• Emotional control under threat

• Speed of recovery between bouts

Without understanding this, fighters simply train harder to compensate, often making the problem worse.

With understanding, training becomes cleaner, sharper, and far more sustainable.

➡️ IN PART TWO, we will look at how to deliberately train the nervous system itself using intensity, breathwork, and controlled stress exposure, rather than allowing it to be shaped accidentally by poor training habits.