The Broadcast / The Science Of Cold Water Swimming

The Science Of Cold Water Swimming

Knowing the benefits of time spent in the sea, we’re focussing on stories of blue health and the therapeutic power of water. A swim instructor based near our Bristol store, Laura Nesbitt dives into the science and benefits of cold water swimming.


4 min read

Written by Laura Nesbitt

Images by Brad Wakefield

Laura wears The Adelie Robe, our warmest towelling changing robe, perfect for wrapping up after a particularly cold swim.


Swimming in cold water during late autumn, winter, and early spring is the most alive and present you will ever feel. Swimming or dipping in anything below 10 degrees produces a pleasant mixture of burning and tingling sensations predominantly in your hands and feet. The longer you stay in the water the greater likelihood the same sensations will travel to the rest of your body. That’s not to put you off, it just makes the sensation when you are getting dry on land that much more euphoric. The sense of calm can last for days.

‘I swim, therefore I am’ seems to be the life affirming personal campaign of every body and every mind that has crossed the line from land to water during the pandemic.  

So many of us during the pandemic have been deprived of touch, a highly significant dimension of the human experience. We are social creatures that rely intensely on community. As a result of our need to be socially accepted, we rely on touch as a way of processing that we are accepted and safe.

Our bodies are biologically designed to respond to touch through receptors in our skin. When we get into cold water our skin stings, a map of nerve receptors called ‘CT afferents’ which are mainly found in the composition of hairy skin that covers most of our body responds to the stimulation of water that moves across our skin and the temperature of the environment by firing signals to our brains.

When our bodies are stressed or we sense a threat, we experience the fight-flight-freeze response, a heightened state of arousal. Our brain will process signals of stress in the amygdala, a part of the brain that evolution has designed to primarily process emotions associated with fear. The hypothalamus, the ‘command centre’ of the brain receives a signal to say you are under attack, stimulating a release of cortisol and adrenaline. This response, passed down from our ancestors puts our bodies into a state of acute stress. The same stress response happens when we enter the water. Your heart rate and breathing will increase rapidly, delivering the energy and oxygen needed to provide the elements you need to either ‘fight, fly or freeze’.

Unlike our ancestors, we’re not likely to be under attack from a lion, we’re just entering cold water. Depending on how acclimatised you are, it can take up to 10 minutes to adapt and regulate your breathing. Regularly entering cold water induces the hormone response a lot more, this response is the first stage to adaption. When we swim, we burn the cortisol up and produce endorphins which result in a feeling of wellbeing once we are back on dry land. It is as though our nervous system literally chills out.

Touch is something we associate with emotional closeness. This is significant not just in the landscape of our minds, but in our bodies too.

The benefits of touch that we have craved through the pandemic are not just emotional and social but also physical. The pandemic challenged what is at the core of what makes us human: social engagement and belonging. The virus asked us to replace touch with space and social interaction with social distance. But there is so much more than social distancing that we need to come to terms with. The governments guidelines required us to not only socially distance but also isolate. These have had profound impacts on our mental wellbeing. The benefits of touch that we missed out on are not just emotional and social but also physical. Touch can reduce pain and stress, as well as giving us a general feeling of wellbeing. I don’t know a single swimmer who doesn’t leave the water without a glowing complexion and a sunny mood from receiving a hug from the water.

Frequently, anecdotal evidence is quoted in the media in relation to the rise of swimmers - particularly those who are female - who make claim to how swimming outdoors is like receiving a hug. Hugging and other forms of nonsexual touching cause your brain to release oxytocin, known as the bonding hormone. The mythological stereotype ‘Men Are From Mars, Women Are from Venus’ might have something to do with this, each gender is accustomed to its own set of emotional balances and values.

When we think of places that make us feel good our immediate line of thought takes us to places that have attached meanings – celebrations, family, friends – locations that have accommodated making memories. Memories by their nature create an intensely personal set of meanings, meanings that make it distinct from other places. Personal experience which often involve literally dozens of small moments of touch helping us to connect and bond, this is the first way in which we connect meanings to place. When we swim, the immersion of water elevates our experience of touch, the most intimate of the senses.

At birth the skin makes a significant adaption leaving the womb and acquiring its first sense of the world. You skin will feel air for the first time, leaving the comfort of floating in amniotic fluid behind. Swimming outdoors is an activity that requires little to no clothing, so many of us have enjoyed the exhilarating feeling of skinny dipping. Perhaps swimming outdoors is a primal soothing nostalgia where we are subconsciously reminded of the weightlessness and protection of our mothers’ wombs.

There is a defining energy about being in cold water and sharing that with strangers and friends alike is the best feeling in the world. No calendar or swimming day is the same and every day is a new beginning. The great thing about any new beginning is that it’s a blank canvas, you can swim yourself to a completely new you, something we can all relate to as a result of the stressed conditions we have been living in.

So many of us have and will continue, to root our sense of wellbeing and mental health to swimming in cold water and the bonds made in the community around it. Perhaps this is why cold-water swimming, a life affirming multi-sensory experience that causes a cascade of physiological overload in our bodies has been so popular during lockdown.


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