Stress Is A Prediction, Not An Alarm
You're outside the room. Two minutes until you go in. You've done this a hundred times and you know what to do - but your mouth has gone dry, your heart is thumping, and you're wondering whether you've got time to nip to the loo again.
That's stress. Most of us have been taught to read it as a bad sign, as evidence we're not coping, or that something has gone wrong. It's neither. What you're feeling is one of the most sophisticated survival systems you own, doing precisely what it evolved to do. Short bursts of it sharpen focus, speed up thinking, and prepare you to meet whatever is in front of you. Whether it helps you or costs you comes down almost entirely to what happens next.
So what is stress, really? And what is actually happening inside your brain and body when you feel it? Let's get into the science and why learning to work with stress, rather than against it, might be one of the more useful things you do for your long-term health.
If you have 10 seconds and want the essence before the why: stress is your body mobilising resources to help you meet what's in front of you, and it does that job well. Two things decide whether it helps you or costs you 1) how you read the moment while you're in it, and 2) whether your body ever gets the message that the moment has passed.
The Adaptive Brain: Why Stress Is a Prediction, Not an Alarm
Your brain is not primarily a reactive organ. It's a predictive one. Its central job is to keep a body alive by anticipating what that body is about to need, and releasing resources before they're required - using information from inside you and around you to forecast what's coming and adapt to it in advance.
This is what I mean by the adaptive brain: not a set of fixed structures waiting to be triggered, but interdependent networks that predict, and adapt to, whatever the moment is about to ask of you.
Think of it as a budget. Every action costs something: glucose, oxygen, salt, water, effort. Your brain's continuous, mostly unconscious task is to forecast the spend and fund it in advance. Stand up, and your blood pressure rises before you're upright. A brain that waited to react would leave you on the floor.
Two roads in
There are two ways a demand gets costed.
The first is fast and subcortical. Sensory information takes a short route to the amygdala, which can flag significance in tens of milliseconds, before your cortex has finished assembling a conscious picture of what you're even looking at. It's the route that makes you jump at a snake-shaped stick.
The second route is slow, cortical, and it's the one that runs your life.
It might be an unread email, an upcoming performance review or a difficult conversation with your partner. None of these can be detected, there's nothing there to see. They have to be evaluated: held in mind, weighed against your resources, projected forward in time. That work happens in the cortex and hippocampus. Only then does the demand get priced.
This is what our unusually large cortex buys us. Alone among animals, we have language and symbolic representation, which means we can hold in mind a danger that isn't here. We can time-travel, and we can teleport. From the comfort of your bed, you can think yourself back into your place of work and into that difficult meeting and… your body will fund the trip. Your autonomic nervous system responds much the same whether you are standing in front of the sabre-toothed tiger or vividly imagining that you are.
We are the animal that can trigger a survival response with a thought.
Why You Need a Wee Before You Go On
That "nervous wee" before a big presentation? That's your body pulling resources away from digestion to pay for something it has decided matters more. The sudden dry mouth under pressure? Saliva production stops, because digestion doesn't matter much when your brain thinks you're about to need everything you have. The jittery, on-edge feeling that stays with you? That's the funding still in place, long after the moment has passed.
Stress can feel like your body betraying you. Really, it's your body backing you, sometimes for longer than the moment required.
When Stress Turns Against You: The Cost of Chronic Stress
Acute stress is a superpower. Chronic stress is a different story.
Your stress response was built for demands that resolve.
Modern demands rarely resolve.
The deadline doesn't chase you across a plain and then disappear. It sits in your inbox.
A zebra runs a magnificent stress response while the lion is chasing it. Then, if it lives, it goes back to grazing. The threat ended, so the stress response ends.
Humans, though? We stay tethered to what has happened, or to what might happen next.
We call that rumination, from the Latin ruminare: to chew over. Grazing animals do it literally, chewing the cud again and again. We do it metaphorically, chewing over past threats and imagined futures. It's the same word for a reason and it's why the demand never resolves. You keep re-serving it.
So the stress response remains in place. Your body never gets the message that the moment has passed, because as far as your brain is concerned, it hasn't.
Over time, that takes a toll:
Changes in brain function - chronic stress affects memory, learning and emotional regulation, making it harder to think clearly and stay steady.
Mental fatigue - decisions start to feel harder, patience thins, and motivation drains away.
Lowered immunity - sustained cortisol suppresses your defences, so you catch things more easily and recover more slowly. A short, sharp stress response does the opposite: it primes immune function. It's the marathon that wears you down, not the sprint.
Strain on the heart - Ongoing stress keeps blood pressure elevated and can contribute to tension in the body, affecting long-term heart health.
Hormonal imbalance - Stress can impact metabolism, energy levels, and even sleep, leaving you feeling off-kilter.
The Stress Spectrum: Eustress vs. Distress
Not all stress is created equal. Psychology draws a useful line between two kinds:
Eustress (Positive Stress) - Motivating and performance-enhancing, such as the adrenaline rush before a big presentation or the focus that comes with a challenge.
Distress (Negative Stress) - Overwhelming and paralysing, leading to anxiety, exhaustion, and a sense of helplessness.
The physiology of these two states is often almost identical. What separates them happens in the appraisal - in how you read what your body is doing.
Which brings us to the real heart of this.
Challenge vs. Threat
What is this going to cost me, and have I got this?
When you sense that a demand is difficult but that your resources are equal to it, your body enters a challenge state - energy mobilised, focus narrowed, funds released against a forecast you can cover. You actually perform better.
When you sense that the demand outstrips what you have, your body drops into a threat state - and the same stress drains you rather than fuelling you.
Two completely different experiences, and two completely different outcomes, decided not by the situation, but by predictive calculations run in your brain.
And importantly, your brain doesn't price the world from scratch each morning. It prices the probable world - the one it has learned to expect.
Early adaptations become the starting point for later ones. If your early life held repeated experiences of fear, threat and loss, your brain will forecast more fear, threat and loss. A sensitive fight response - quick to spot danger, quick to defend - is an entirely understandable adaptation to a world where vigilance was the basis of survival.
Which means the answer to ‘have I got this?’ isn't only about this moment. It's shaped by every moment your brain has already learned from.
You see this most clearly in sport. Two athletes can arrive at the same start line with the same racing heart, and the one who reads it as a challenge will tend to outperform the one who feels threatened by it.
But you don't need to be an athlete for this to matter, because it plays out exactly the same way in the meeting you've been dreading, or the conversation you keep putting off. The stress is coming either way. What's still open is how you meet it.
So much of managing stress well happens right there, in how you answer that question. What is this going to cost me, and have I got this?
And before you answer: you almost certainly have more than your brain has counted.
It leans toward danger. It always has. Mistake a stick for a snake and you jump at nothing, feel foolish, and walk on. Mistake a snake for a stick and you don't get to make that mistake twice. So your brain learned to err toward the snake, every time, because erring the other way only ever had to be wrong once.
That caution is why you're here at all. It's also why your brain answers have I got this? before it has properly looked. The work, then, is looking. Partly that means separating old fears from what's actually in front of you. And partly it means practice - real practice - with the sensory and cognitive strategies that shift you into challenge rather than threat. The rest of this article is about both.
How to Work With Stress
The aim here is regulation. Turning stress up when it serves you, and helping your body get the message when the moment has passed.
Here are some evidence-based ways to help your body and mind handle stress more effectively.
Answer the question on purpose. Your brain will answer have I got this? whether you ask it to or not, and it'll answer from memory. Self-talk is how you get a vote.
Don't tell yourself to calm down. You're demanding a state you can't reach and don't need, and now you've got two problems. Reappraise the arousal instead: this is my body getting ready. This is my body backing me. People told that a racing heart is functional rather than dangerous shift measurably toward a challenge profile, and they perform better for it.
Then count what you've got, out loud if you need to. You know this material. You’ve done this a hundred times. Just take one step at a time. You’ve got this.
And try "you" rather than "I". You've got this tends to outperform I've got this; a little distance from yourself seems to help you believe the words more.
Exhale. Your body has a brake as well as an accelerator, and the exhale is where you'll find it. Vagal tone peaks as you breathe out, which is why slow breathing with a long out-breath settles you and fast shallow breathing alerts you.
Move your body. Your brain released the fuel for physical action, and then you sat in a meeting. Exercise is that action, finally arriving. It lets the body finish what it started, instead of spending the day with the engine running and nowhere to drive.
Reach for Connection. You're a mammal, and the word itself means nursing. Every one of us began life unable to feed, warm or settle ourselves, entirely dependent on another body to do it for us. Your nervous system learned to calm in the presence of another nervous system long before it learned to calm alone and that doesn't switch off when you grow up. Reach out for help and let others help you - it’s what’s we all need (and what helps us perform at our best).
Protect your sleep. Sleep is essential. When stress is high, sleep matters more, not less, which is unfortunate, because it's usually the first thing to go.
Take small doses. Small deliberate doses of manageable discomfort - a cold shower, a hard session, learning a new skill - teach your brain something it can only learn by experience: that this was survivable, and you came back from it. That's how the estimate gets revised, by giving it new evidence, in doses you can survive and recover from.
Some fears need answering at the source. Everything else here helps you handle what your body is doing. This is about where it learned to do it.
Some of what your nervous system expects, it learned young - from a house, or a relationship, or years where being ready was the sensible thing to be. It made sense then. It probably kept you safe. And your body has been faithfully applying that lesson ever since, to meetings and messages and people who were never the original threat. No amount of slow breathing will teach it otherwise.
That's what therapy is for. Approaches like EMDR and trauma-focused CBT are built for memories that never got properly processed at the time. They bring them back safely, with support, so they can settle at last and stop speaking for situations they know nothing about.
It's slower work, and it isn't done alone. But it's the difference between managing the fear and letting it finally be over.
Two Minutes to Go
So, back to that corridor. Two minutes to go before you step inside.
That's not your body turning on you. That’s your body turning up for you.
Go in.
Warmly,
Matt
Dr Matt Slavin
Clinical & Performance Psychologist
Auckland · Online
