High Performance Isn’t Just Mental – Here’s One Thing People Often Overlook

We spend a lot of time trying to improve performance by thinking better.

Better strategies, better decisions, better analysis under pressure.

And while that matters –

It’s only part of the picture.

Because there’s something that often gets overlooked.

The state of your nervous system.

And here’s the thing – if your nervous system is dysregulated, your thinking is already compromised. No amount of mental effort will fully override that.

Your Body Is Already in the Conversation…

And it’s part of this more than most people realise.

Long before you consciously evaluate a situation, your body has already made a call. Stephen Porges’ Polyvagal Theory helps explain why. Your nervous system is constantly and automatically scanning your environment for cues of safety or threat – a process Porges calls neuroception.

And depending on what it detects, it shifts your state.

Threat detected → you mobilise or shut down. Safety detected → you access clarity, connection, and control.

This isn’t mindset. It’s biology.

And it’s happening underneath each conversation, each decision, each performance moment.

Two Concepts Worth Separating…

Polyvagal Theory and the Window of Tolerance are often used interchangeably. They’re not the same thing, and the distinction matters.

Polyvagal Theory, developed by Porges, maps the states of your nervous system – ventral vagal (calm, clear, connected), sympathetic (activated, reactive, urgent), and dorsal vagal (shut down, disengaged, low energy). It tells you what state you’re in and why.

The Window of Tolerance, introduced by Dan Siegel, describes the range of arousal where you can actually function well. Inside that window, you can think, decide, connect, and perform. Above it, you’re hyperaroused – anxious, reactive, scattered. Below it, you’re hypoaroused – foggy, flat, disengaged.

Put simply: Polyvagal Theory maps the terrain. The Window of Tolerance tells you whether you’re on or off the performance edge.

Why Thinking Harder Often Makes It Worse…

When things go wrong, most high performers default to thinking.

They analyse, they replay, or maybe they try to solve it in real time.

You know the moment – a mistake in a game, something off in a meeting. The brain speeds up. You start going over it. And instead of recovering, performance drops further.

Not because you lack skill or awareness.

But because your state has already shifted – and your thinking has followed it.

Research by Thayer and Lane points to something important here: a significant portion of communication in the nervous system flows from body to brain, not the other way around. Which means the state your body is in shapes the quality of the thinking that follows.

And that’s a very different conversation to the one most high performers are having with themselves.

Small Signals, Real Impact

This is where the concept of glimmers becomes relevant – a term developed by Deb Dana, building on Polyvagal Theory.

Glimmers are small, often unnoticed moments that signal safety to the nervous system.

A steady breath before a key moment. The feeling of feet on the ground. Eye contact with a teammate after a mistake. A calm voice in a tense room.

Individually, they seem insignificant. But they influence whether your system moves back toward a regulated state – back inside your window – where clear thinking and effective performance actually live.

What This Looks Like In Practice

In sport, the margin is small. Two athletes, same skill level, same preparation. One spirals after a mistake – rushing, forcing, trying to make up for it. The other pauses, reconnects, resets. The difference isn’t talent. It’s state.

In leadership, the stakes are different but the dynamic is the same. When pressure rises in a room and someone reacts – tone sharpens, thinking narrows, people either go quiet or defensive. Now compare that to a leader who slows things down, speaks calmly, creates space. Same problem. Completely different outcome.

Leaders can influence results. What’s often missed though is that they can also influence the nervous systems of the people around them.

The Reframe…

High performance isn’t just about thinking better.

It’s about being in a state where your thinking can actually work.

Like all evolving science, aspects of these models continue to be explored and debated – but the underlying principle, that physiology shapes performance, is well supported across the research.

The physiology comes first. The performance follows.

And once you understand that – it changes how you read a moment. In yourself, and in the people you lead.

References

Dana, D. (2018). The Polyvagal Theory in Therapy: Engaging the Rhythm of Regulation. New York, NY: W. W. Norton & Company.

Porges, S. W. (2011). The Polyvagal Theory: Neurophysiological Foundations of Emotions, Attachment, Communication, and Self-Regulation. New York, NY: W. W. Norton & Company.

Siegel, D. J. (1999). The Developing Mind: How Relationships and the Brain Interact to Shape Who We Are. New York, NY: Guilford Press.

Siegel, D. J. (2012). The Developing Mind (2nd ed.). New York, NY: Guilford Press.

Thayer, J. F., & Lane, R. D. (2009). Claude Bernard and the Heart- Brain connection: Further Elaboration of a Model of Neurovisceral Integration. Neuroscience & Biobehavioural Reviews, 33(2), 81–88.