The science of stretching, loading and why muscles changes everything above the neck.
Most of us do not realise how deeply our daily routines shape the way our bodies feel. Hours spent sitting at a desk, looking at screens, carrying stress from one part of the day into the next, or scrolling long after we should have rested all leave a physical imprint.
The shoulders begin to rise. The hips lose their mobility. The spine becomes less fluid. Gradually, the body tightens around the habits we repeat, until stiffness starts to feel normal.
We tend to think of stretching as a purely physical solution. A muscle feels tight, so we lengthen it. The tension eases, movement feels better and it seems as though the problem has been resolved.
But the body is far more intelligent than that.
What we experience as stiffness is not always simply a shortened muscle. It can also be the nervous system responding to the way we live: how often we sit, how we breathe, where we hold tension, how we brace under pressure and which movements we repeat or avoid each day.
The body does not just remember what we do. It adapts to it.
What is stretching
The best place to begin is by understanding what stretching actually is. At its simplest, stretching is the deliberate act of taking a muscle, tendon, joint or the surrounding connective tissue into a longer range of movement. We do it to ease tension, improve mobility and help the body feel more comfortable moving through a greater range. Physically, stretching takes the body towards the edge of what feels comfortable. Neurologically, it is a conversation with the nervous system.
The sensation of tightness is not always a sign that a muscle is physically too short. Sometimes, it is the nervous system deciding that a particular range of movement does not yet feel safe. By moving slowly, breathing steadily and staying within a manageable level of sensation, we begin to show the body that it does not need to resist or protect itself quite so strongly.
This may also explain why stretching can feel emotionally releasing. Tension is not only held in the muscles. Stress can shape the way we breathe, stand, sit and brace ourselves throughout the day. Over time, those patterns become familiar to the body.
Stretching, then, is not simply about making a muscle longer. It is a process of helping the body feel safe enough to soften, move more freely and gradually let go.
What a Stretch Is Actually Doing
Stretching is not simply something we do before or after exercise, nor is it a purely mechanical act. It is partly structural, but heavily neurological. It may begin with muscles and joints, but the nervous system is involved at every stage.
When a muscle is stretched, sensory receptors called muscle spindles detect changes in its length and movement. They send this information to the spinal cord and brain, helping the nervous system decide how the body should respond. There is a second set of receptors, Golgi tendon organs, found where the muscle meets the tendon, When a stretch is sustained, held for thirty to sixty seconds rather than briefly released, the Golgi tendon organs trigger what is called the inverse myotatic reflex. This is a direct neurological signal that instructs the muscle to release tension rather than resist the stretch. The body is not being forced open. It is being given a signal it already knows how to follow.
This is why a stretch held patiently feels drastically different from one that is rushed. The nervous system needs time to receive the signal, process it and respond. Patience in stretching is not simply a matter of comfort. It is the difference between a mechanical pull and a genuine neurological release.
Beyond the muscle itself, sustained stretching has measurable effects on the autonomic nervous system. Research on yoga-based stretching consistently shows reductions in salivary cortisol, the body’s primary stress hormone, increases in heart rate variability, the key marker of parasympathetic nervous system activity we have explored in The Still Room, and a measurable shift from sympathetic toward parasympathetic dominance. A stretching practice is a nervous system regulation practice.
The Tissue That Holds More Than We Know
This is the part I find most meaningful, because it explains something many of us have felt but never quite understood.
The body contains a system called fascia. It is the connective tissue that wraps through and around every muscle, organ, nerve and structure in the body. For a long time, fascia was treated almost like packaging, the tissue you moved aside to reach the things that mattered. That understanding has changed significantly in recent decaded.
Fascia is now understood to be deeply sensory. It is not just holding the body together; it is listening. It responds to stress, movement, hydration, temperature and the state of the nervous system.
It is not passive. It is a sensory organ. It is in constant communication with the autonomic nervous system, responding to stress, movement, hydration and temperature. And crucially, research has found that it responds to chronic stress in measurable ways. When the body lives in stress for too long, fascia can become denser, tighter and less fluid. It starts to lose that easy, mobile quality we feel when we are rested, regulated and moving well.
This matters because so much of what we call “tightness” is not just muscular. It can be the body’s response to how long we have been bracing, holding, coping or pushing through. The jaw that never fully softens. The hips that feel locked. The shoulders that sit high even when the day is over. The body remembers patterns before the mind has language for them.
Emerging research in fascial science suggests that this tissue also plays a role in what might be called somatic memory, the body’s holding of the physical imprint of accumulated stress and emotional experience. This is not a fringe idea. Research published in peer-reviewed journals in the field of neuroscience and bodywork has documented the relationship between fascial restrictions and the body’s stress response and emotional regulation. It has found that releasing fascial tension through sustained stretching, mindful movement and myofascial techniques produces effects that go beyond physical mobility into something that resembles emotional processing.
This is why certain stretches produce unexpected emotional responses. Why a deep hip opener in a yoga class sometimes releases something that was not purely muscular. Why the cry that occasionally arrives in a long hold is not weakness or strangeness but the body completing something it has been holding too long. The tissue is releasing what the nervous system stored there. And the body, given the right conditions, knows exactly how to let go.
What Happens When You Lift Something Heavy
Stretching and loading are two different conversations with the body. And both are necessary.
When a muscle contracts under sufficient resistance, the body doesn’t simply build strength. It initiates a complex cascade of neurological, hormonal and biochemical responses that extend well beyond the muscles, profoundly influencing brain function, mood and mental wellbeing.
The brain releases a protein called BDNF, which stands for brain-derived neurotrophic factor. It is sometimes described as fertiliser for the brain because it supports the growth of new neural connections, protects existing neurons from damage and is one of the most potent natural antidepressants the body can produce. Exercise, and resistance exercise specifically, is one of the most reliable ways to stimulate BDNF production available. Research consistently shows that the neurological effects of resistance training on mood, cognitive function and emotional resilience are significant and sustained.
Alongside BDNF, resistance training stimulates the release of dopamine, serotonin and norepinephrine. These are the neurotransmitters most directly associated with motivation, mood stability, emotional resilience and the capacity to handle stress without being overwhelmed by it. The mental clarity that follows a session of lifting is not imagined and it is not simply the relief of having finished. It is a measurable neurochemical state. The brain has been given a significant and evidence-based intervention.
Research has also found that resistance training has particular significance for women, especially in midlife. As oestrogen declines during perimenopause and the years that follow, the nervous system becomes more sensitive to cortisol and more reactive to stress. The hormonal buffer that oestrogen provided to the HPA axis, the body’s central stress response system, diminishes. Resistance training directly rebuilds some of that buffering capacity. It reduces baseline cortisol, improves the body’s stress recovery speed and supports the hormonal landscape at exactly the point it is most vulnerable.
The Psychological Shift That Nobody Talks About
There is a dimension to lifting that sits beyond the neurochemical and I want to name it directly because it has been one of the more quietly significant experiences of my own relationship with movement. When the body lifts something genuinely heavy, something at the edge of what it believes it can manage, and it manages, something shifts in the relationship between the person and the body they inhabit.
It is not the same as achieving a goal or completing a task. It is more embodied than that. More immediate. The body has just demonstrated something to the mind that the mind was not entirely certain of. That there is more capacity here than was assumed. That the limit was further out than it appeared. That this body, carrying everything it carries, the fatigue and the responsibility and the accumulated weight of a full life, is also capable of this.
That knowledge does not live in the head. It lives in the body. And it changes the way the body is inhabited afterward in a way that is subtle and durable and very difficult to replicate through any other means. For women who have spent years in primarily relational and service-oriented roles, this experience of discovering embodied capability can be genuinely transformative. Not because the physical strength is the point but because the trust between mind and body that it builds is.
Strong Does Not Mean Painful
I want to address something directly before closing because it comes up consistently in conversations about women and strength training. Strong does not mean painful. Heavy does not mean hard on the body. Challenging does not require suffering. The nervous system does not benefit from being overwhelmed. It benefits from being progressively challenged and then given adequate recovery. A stretch held at the edge of comfort, not past it, produces neurological release. A weight that is genuinely challenging without being injurious produces the neurochemical response described above. The body does not need to be punished to be changed.
What it needs is to be used. Deliberately, consistently and with enough attention to feel what is actually happening rather than simply enduring until it is over.
The feeling at the end of a good session of stretching or lifting is the body’s honest signal that something useful has happened. Not just in the muscles. In the nervous system. In the hormonal landscape. In the quiet space between the physical and the mental where so much of a woman’s daily experience actually lives.
That feeling is worth understanding. Because once you understand it, you stop waiting for the right conditions to begin. You start seeking it out instead.
Explore The Still Room for more on the science of movement, the nervous system and intentional living. Also see Yoga Asanas Card Deck – Ahloki to help with some good streches to get you started. The Ahloki ritual collection was built around the understanding that how we inhabit our bodies matters as much as what we do with them.
