Exercise
Healthy Life
Why wild swimming could be good for you – and your brain
July 31, 2024
Wild swimming. Millions of us do it and, when asked why, the overwhelming answer is the feeling of joy it brings. According to a survey by The Outdoor Swimming Society, 94% of us feel happier and less stressed after a dip in the cool waters of a lido or lake.
But what’s behind that sense of exhilaration – and how else is wild swimming good for our mind, mood and brain? Might it even help cut the risk of dementia?
If anyone knows the answers to these questions, it’s Professor Mike Tipton of the Extreme Environments Laboratory at the University of Portsmouth. He’s spent 40 years studying how the body responds to cold water, goes outdoor swimming himself (typically to prepare for Ironman contests) and has worked with everyone from the Royal Navy to UK Sport. He recently took some time out to speak to Brain Health Network.
Let’s start with that sense of joy, the feeling of being wide awake and hyperalert. The shock of being immersed in cold water leads to levels of dopamine and serotonin, neurotransmitters involved in reward processing and happiness, shooting up. A rush of endorphins provides pain relief and also adds to the sense of euphoria. The sense of achievement that comes with overcoming the cold can also be empowering, says Professor Tipton.
Does that feeling last all day? Some people say so, says Professor Tipton. “But the other thing that happens is that most of them tell us that they were fast asleep by seven o’clock in the evening.” The theory being that because wild swimming is such an unusual form of exercise, and so stimulating, it improves sleep later in the day.
People also describe how their troubles melt away when wild swimming. You “may have all kinds of problems but when you are faced with the challenge of the cold, that tends to be the only thing you focus on at the time,” says Professor Tipton.
But wild swimming may also help with longer-term stress relief. A recent study looked at whether outdoor swimming could help improve symptoms of stress and work-related burnout in frontline NHS workers. After eight sessions in an outdoor pool in London or in the sea in Cornwall, the doctors, nurses, physiotherapists and admin staff felt less burnt out, professionally and personally. They also reported a 15% increase in mental wellbeing.
One possibility is that after the body gets used to cold-water swimming, it finds it easier to cope with other types of stress too. That stress could be emotional, such as the pressures of work, or physical, such as lack of oxygen when climbing. “Somewhere probably at cellular level, some of the responses to stress probably share a common pathway,” explains Professor Tipton. “And if you can adapt that pathway, or habituate it, by repeated immersions, for one stress, it may well be that it has a benefit to another.”
Some research suggests that going swimming regularly in cold water lowers inflammation. Inflammation plays a vital role in the healing of wounds and in fighting off infections but if lingers after the cut heals or the virus is vanquished, it can damage healthy tissue. This kind of chronic inflammation is associated with a host of diseases, from cancer to dementia.
Wild swimming may protect against dementia in other ways, too. Research from the University of Cambridge has shown people who regularly swim outdoors during the winter have higher levels of RBM3, a protein that triggers the growth of new connections between brain cells. These connections, or synapses, carry information between brain cells, and are damaged and lost in Alzheimer’s.
A recent study found that increasing levels of RBM3 protected mice against degenerative brain disease – but it’s too early to say if the protein also wards off conditions like dementia in people, says Professor Tipton.
He’s also keen to stress that the evidence for a lot of the health claims about wild swimming is anecdotal. Definitive studies haven’t been done to back them up; those studies that have been done often lack proper control groups. That means that rather than comparing wild swimming with swimming in an indoor pool, for example, they compare it against not doing any extra exercise at all.
The result is that while there are lots of theories about why wild swimming is good for the mind and brain, no one really knows that the active ingredient is. After all, meeting up with friends, exercising, being immersed in water, surrounded by nature and enjoying a slice of cake (a post-swim ritual for many) can all have benefits.
Wild swimming carries risks too, from heart problems, to drowning, to hypothermia. Follow Professor Tipton’s top tips to stay safe in the water and enjoy it, too:

Link: “Cold water therapies: minimising risks” British Journal of Sports Medicine
Next: read “Why Exercise Can Benefit Brain Health If You’re Over 50” to understand the role of exercise on the brain.
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