Today is Samaritans Awareness Day – a reminder that checking in on our mental health matters, every single day. The Samaritans are available around the clock on their free helpline, 116 123, because distress doesn't keep office hours, and neither does the nervous system that underpins it.
This is a timely prompt to talk about something we rarely address honestly: what chronic stress does to the body, and why it can feel physically impossible to come down from it. Because if you've ever been told to "just relax" and felt worse, or more wound up, or strangely guilty for not being able to switch off - that's not a personal failing; it’s biology.
Chronic stress leaves measurable biological wear and tear. Research shows this 'allostatic load' - the cumulative cost of sustained physiological stress responses - is one of the biggest predictors of mortality disparities, accounting for around 35% of the difference in lifespan between high and low socioeconomic groups (1). We're not talking about feeling a bit tense. We're talking about structural, cellular-level impact.
In this article, we'll explore why the nervous system gets stuck in overdrive, why trying to relax can sometimes make things worse, and what evidence-based approaches help the body find its way back to calm. We'll look at the vagus nerve, heart rate variability, the endocannabinoid system, and the simple daily inputs that create the conditions for genuine regulation.
As a Clinical Nutritionist, I regularly speak with clients stuck in chronic activation who believe they're failing at relaxing. They're not. Their nervous system is doing exactly what it was designed to do - it just hasn't had the signal that it's safe to stop.
Nervous system dysregulation: why most of us are stuck in fight or flight
The autonomic nervous system operates in two primary modes. The sympathetic nervous system is the accelerator - it activates the classic 'fight or flight' response, flooding the body with adrenaline and cortisol, sharpening focus, tensing muscles, and diverting energy away from anything non-essential. The parasympathetic nervous system is the brake - the 'rest and digest' state where heart rate slows, digestion resumes, immune function is restored, and the body repairs itself.
In an ideal world, the body moves fluidly between these two states: activated when threatened, recovered when safe. The problem is that most modern lives don't allow for that recovery. The nervous system evolved to handle short, intense bursts of stress - a predator, a conflict, a physical threat. It wasn't built for inboxes, commutes, financial pressure, and relentless connectivity operating simultaneously, indefinitely.
The result is what's increasingly referred to as a dysregulated nervous system: a system chronically tilted toward sympathetic dominance, where the brake is either permanently lifted or barely touching the pedal.
It's worth briefly mentioning the polyvagal theory here - the framework developed by neuroscientist Stephen Porges that maps the nervous system's layered responses to safety and threat. It's a rich and fascinating area that deserves its own full exploration (and we'll come back to it), but the central insight is useful: the nervous system isn't simply on or off. It's constantly scanning the environment for cues of safety or danger, often below the level of conscious awareness.
What matters most right now is this: a dysregulated nervous system isn't a sign of weakness or poor emotional regulation. It's a learned pattern - often shaped by prolonged stress, trauma, or simply a life that has demanded more than it has allowed the body to recover. Understanding that changes everything about how we approach it.
Why you can’t just relax (and why trying might make things worse)
If you've ever typed 'why can't I relax' into Google at midnight, you're not alone.
Here is the frustrating paradox at the heart of chronic stress: the act of trying to relax can actively prevent it.
When we attempt to consciously force calm, counting breaths with one eye on the clock, willing ourselves to switch off, monitoring whether we feel relaxed yet - we're engaging the very monitoring and evaluation systems that keep us alert. The brain treats "am I relaxed?" as another problem to solve. And problem-solving is sympathetic territory.
There's also a crucial distinction to draw between regulation and suppression. Suppressing a stress response - pushing it down, distracting from it, performing calm - is not the same as resolving it. The physiological activation is still there; it's just been temporarily overridden. Think of it like holding down the lid of a boiling pot rather than turning down the heat. The nervous system, in its wisdom, will find its way back to that unprocessed activation.
This is partly why so many people find that the moment they stop - on holiday, at the weekend, after a big project - they feel worse before they feel better. The body has been waiting.
Culturally, we've inherited a narrative that treats calm as a personality trait, or even a moral achievement. "She's so zen". "He never lets anything get to him". Calm gets positioned as something the disciplined, grounded, mentally strong people have - and the rest of us are simply not trying hard enough. This framing is not only unhelpful, but it's also inaccurate. Calm is not a decision. It's a physiological state that the body reaches when it feels safe, supported, and regulated.
How to activate your parasympathetic nervous system: what calm actually looks like in the body
Genuine calm is measurable. When the parasympathetic nervous system is active, heart rate slows and becomes more variable, digestion resumes, immune function is restored, muscles release, and the prefrontal cortex - the part of the brain responsible for perspective, decision-making, and connection - comes back online.
One of the most useful markers of nervous system health is heart rate variability, or HRV. Unlike heart rate itself – which simply measures beats per minute – HRV measures the variability in the time between heartbeats. A healthy, flexible nervous system produces high HRV: the heart speeds up slightly on the in-breath and slows on the out-breath, reflecting the body's responsive, dynamic capacity to adapt.
Low HRV, by contrast, is increasingly recognised as a sign of a system stuck in sympathetic dominance. Low HRV symptoms include poor sleep, fatigue, difficulty concentrating, heightened anxiety, and a reduced capacity to recover from stress. HRV isn't just a fitness metric - it's a window into nervous system resilience. And crucially, it responds to the inputs we give it.
The good news is that parasympathetic activation isn't a mysterious state available only to experienced meditators. It's a biological gear that the body is always trying to find. Our job is to remove the obstacles and provide the right signals.
Vagus nerve reset: exercises for your body's off switch
The vagus nerve is the primary highway of parasympathetic activation. Running from the brainstem down through the face, throat, chest, and abdomen, it connects the brain to the heart, lungs, and gut - and carries information in both directions. Around 80% of its fibres carry signals upward, from body to brain, which means the state of the body profoundly influences the state of the mind.
Stimulating the vagus nerve sends a direct signal to the parasympathetic system: it's safe to slow down. And unlike many wellness interventions, vagus nerve exercises are evidence-based, accessible, and fast-acting.
Physiological sigh
This is currently one of the most well-supported breathing tools for rapid stress reduction, and for good reason. A physiological sigh consists of a double inhale through the nose - a full breath in, followed immediately by a short additional sniff to fully inflate the lungs - followed by a long, slow exhale through the mouth. The extended exhale activates the parasympathetic nervous system almost immediately, and research from Stanford has shown it to be more effective at reducing stress in real time than other breathing techniques or mindfulness practices (2). One to three cycles are often enough to feel a shift.
Cold water on the face
Submerging the face in cold water - or splashing it - triggers the mammalian dive reflex, which directly stimulates the vagus nerve and slows the heart rate. Even 30 seconds can shift the system.
Humming and singing
The vagus nerve runs through the larynx. Humming, singing, or even gargling activates it through vibration, particularly when sustained sounds are used. This is not incidental, it's why communal singing, chanting, and music have featured in human regulation practices across cultures for millennia.
Slow exhalation
Any breathing pattern that extends the exhale beyond the inhale activates parasympathetic tone. A simple 4-7-8 pattern (inhale for 4, hold for 7, exhale for 8) or simply focusing on making the out-breath longer than the in-breath is sufficient. It doesn't need to be complicated.
The endocannabinoid system’s (ECS) role: the missing link for nervous system regulation
There's a body system that rarely comes up in mainstream conversations about stress -and it may be one of the most important.
The endocannabinoid system (ECS) is the body's internal regulatory network, present in virtually every organ and tissue. Its primary role is homeostasis: keeping the body's systems in balance. It modulates mood, pain perception, inflammation, appetite, sleep, and - crucially for our purposes - the stress response itself.
The ECS operates through endocannabinoids (molecules the body produces naturally), receptors, and enzymes that break those molecules down. When functioning well, it acts as a kind of biological buffer: dampening excessive activation, smoothing out cortisol spikes, and helping the nervous system return to baseline after stress.
The concept of endocannabinoid tone refers to the baseline activity of this system. Some people have a naturally lower tone - a less responsive ECS - which can mean a reduced capacity to naturally self-regulate after stress. Chronic stress itself depletes endocannabinoid tone over time, creating a feedback loop: the more chronically stressed you are, the less equipped the body becomes to return to calm.
This is where CBD (cannabidiol) enters the picture - not as a cure, but as a mechanism worth understanding. CBD interacts with the ECS not by directly binding to its receptors, but by modulating the efficiency of endocannabinoid breakdown, thereby supporting the system's overall tone. It's a complement to the body's own regulation, not a replacement for it.
How to regulate your nervous system: what actually works
If you're wondering how to reset your nervous system after a stretch of chronic stress, the answer isn't a single fix... Regulation isn't a trick. It isn't a single supplement or a breathing exercise you do once before bed. It's a set of inputs - consistent, cumulative, and physiological - that create the conditions for the nervous system to shift.
Breathwork
Breathwork, particularly the physiological sigh described above, is the most immediate lever available to most people. It requires nothing, can be done anywhere, and works in seconds. Returning to it throughout the day, rather than only in moments of crisis, helps build parasympathetic resilience over time.
Movement
Movement is one of the most effective tools for nervous system regulation we have, and arguably the most underused. Not punishing, high-intensity movement pursued through gritted teeth - but regular, rhythmic movement that the body finds tolerable or enjoyable. Walking, swimming, cycling, dancing. These activate the body's natural stress-processing mechanisms and support HRV.
Sleep quality
Sleep quality is where much of the nervous system's repair work happens. Chronic sleep disruption maintains sympathetic dominance; consistent, quality sleep restores parasympathetic tone. This is a circular relationship - a dysregulated nervous system disrupts sleep, and poor sleep dysregulates the nervous system further - which is why addressing both simultaneously matters.
Nutrition
Nutrition plays a quieter but significant role. B vitamins are critical cofactors in the production of neurotransmitters, including serotonin and GABA - the brain's primary calming signal. Magnesium, often depleted by chronic stress, supports muscle relaxation, nervous system signalling, and sleep quality. It's one of the most consistent nutritional gaps I see in clients managing high stress loads, and one of the most reliably impactful to address.
The principle running through all of these is consistency over intensity. The nervous system doesn't reorganise through willpower or grand gestures. It changes with repetition - small, steady inputs that accumulate over weeks, gradually recalibrating the system's baseline.
In clinical practice, I almost always address nervous system regulation before anything else. It's the foundation. Nutritional protocols, sleep interventions, even lifestyle changes – they land differently when the system is no longer in constant threat response. Regulation creates the conditions for everything else to work.
Calm isn't a choice, but nervous system regulation is
If you've ever been told to 'just relax' and felt worse, that's not failure - that's biology. The nervous system doesn't respond to instructions. It responds to safety signals - physiological cues that it's genuinely okay to slow down.
Calm is something the body does when it feels safe, supported, and regulated. It cannot be willed into existence, but it can be cultivated - through breath, through movement, through sleep, through the quiet consistency of giving the body what it needs.
On Samaritans Awareness Day, it feels important to note that for some people, nervous system dysregulation goes deeper than daily stress. If you're struggling, the Samaritans are available 24 hours a day, every day of the year – simply call 116 123. There is no judgement, and you don't have to be in crisis to reach out.
If you're curious about supporting your nervous system through nutrition and supplementation, explore Provacan's CBD for stress supplements range, developed with calm in mind; take our wellbeing quiz to find the right starting point; or book a consultation for more personalised clinical support. There's no pressure - just an open door.
Sources
- ScienceInsights (2024). What is allostatic load? The toll of chronic stress. https://scienceinsights.org/what-is-allostatic-load-the-toll-of-chronic-stress/
- Balban, M.Y., Neri, E., Kogon, M.M. et al. (2023). Brief structured respiration practices enhance mood and reduce physiological arousal. Cell Reports Medicine, 4(1). https://www.cell.com/cell-reports-medicine/fulltext/S2666-3791(22)00474-8
- Porges, S.W. (2011). The Polyvagal Theory: Neurophysiological Foundations of Emotions, Attachment, Communication, and Self-Regulation. Norton & Company.
- Russo, E.B. (2016). Clinical endocannabinoid deficiency reconsidered: current research supports the theory in migraine, fibromyalgia, irritable bowel, and other treatment-resistant syndromes. Cannabis and Cannabinoid Research, 1(1), pp.154–165.
