Cold-water swimming has benefits for the brain as well as the body

It's 8am and I'm standing on the shore of a local lake in Beckenham Place in London, the early morning sun just starting to peek through the trees. A layer of fog rises above the cold water, and everything is quiet – even the ducks do not dare to take a dip today. However, my friend and I are standing in our bathing suits, even though the water temperature is in the single digits. The first step into the water always takes my breath away, but as my body acclimatizes and we swim the wide loop, I feel like a new person.

Over the past few years, I've converted quite a few friends into cold water devotees. My point is simple: nothing improves your mental health like this. Until recently, my case was mostly anecdotal. But as more people take to ice baths, cold showers and winter swimming, researchers are beginning to reveal that it's these freezing dives that affect our brain chemistry. And, as it turns out, my weekly failures can change my brain for a long time.

I'm not the only one who likes to swim in cold water – around 6.8 million people in England now swim regularly outdoorseither in open water or in outdoor pools, which tend to be quite cold for most of the year. This is not surprising, since there is now strong evidence that regular cold water immersion reduces fatigue, reduces symptoms of depression and improves well-being – despite the fact that it also carries some potential health risks, such as hypothermia, illness from dirty water and, in rare cases, heart problems.

For example, in one study, 36 people completed four-month open water swimming program four days a week in winter showed significantly lower stress and fatigue compared to a group of non-swimmers who continued to participate in normal city life with occasional outdoor exercise. The swimming group also experienced increased energy, improved memory and improved mood.

Even solo dive appears to have its benefits: People who stood chest-deep in seawater at temperatures of around 13.6˚C (56.5˚F) for 20 minutes reported decreased negative mood and increased alertness and self-esteem compared to the group that remained on shore.

Cold exposure affects multiple physiological pathways, including the heart and immune system. It is known that ordinary winter swimmers improved immune healthhave fewer colds and reduce the risk of cardiovascular disease. But what intrigues me most is the neurological effects.

For example, the effect on your mood may be due to the fact that exposure to ice water on a semi-naked body causes an acute stress response. If you've ever jumped into a cold ocean or taken a dip at a spa, you know the feeling: Your brain orchestrates a sudden surge of adrenaline, dopamine, and cortisol—a mixture of chemicals that gives you the same high you get after a workout.

From an evolutionary perspective, this is a smart survival strategy. Exposure to extreme cold is life-threatening, so this “cold shock response” provides a boost of energy, increases your alertness, reduces pain, and mobilizes your stress response to help you avoid danger.

This is also the reason why people may face problems when swimming in cold water. Without proper precautions, it can cause sudden inhalation, impaired movement, and in rare cases, cause heart attacks. However, intentionally triggering this response in modern calm lake conditions under the supervision of lifeguards and undergoing the correct training gives me access to its benefits without any danger. Deficiencies of these same chemicals play a critical role in disorders such as depression and anxiety, so artificially boosting them may explain why mood temporarily lifts after swimming.

There may also be long-term consequences. Over time, as the body adapts to cold water, its response to stress changes. In one study, people who swam three times a week in cold water for 12 weeks By the end of the experiment, less cortisol was released than at the beginning, suggesting that the body has learned to cope with stress more effectively. Moderating this response may have long-term benefits due to chronically high levels of stress hormones cause inflammation, which is associated with many diseases and accelerated aging. A recent review of the latest evidence on cold water swimming suggests that this adaptation may have even greater mental health benefits. helping people manage anxietyFor example.

Our response to cold shock also releases proteins such as RNA-binding motif 3, which supports the repair of synapses—the connections between neurons. In mice predisposed to developing Alzheimer's disease, elevated levels of this protein protected them from neurological damage.This has led some researchers to suggest that regular cold-water swimming may have long-term neuroprotective effects in humans as well, although this has not yet been directly studied.

Exposure to cold water also has powerful psychological effects. Overcoming something difficult – and let's face it: even the most avid cold-water swimmers sometimes consider it a test of endurance on icy days – can develop a sense of mastery and self-efficacy, what you might call durability. Add to this the social aspects that are a common part of outdoor swimming, and you end up reflecting some of the factors that treatments such as antidepressants and psychotherapy hope to achieve. Indeed, there is emerging evidence that cold water swimming, as an adjunctive therapy, may improve symptoms of depression. beyond the use of only pharmacological drugs.

Remarkably, researchers are even beginning to directly study the effects of cold water swimming on the brain. For example, Ala Yankouskaya from the University of Bournemouth in Poole, UK, and her colleagues scanned the brains of 33 people who do not normally swim in cold water before and after a 5-minute full-body bath in 20˚C (68˚F) water. This was the first time that researchers had real-time information about How brain networks interact after exposure to cold water.

They found beneficial changes in connections between several major brain regions, particularly the medial prefrontal cortex and parietal lobe—regions associated with emotional control, attention, and decision making. Activity in these areas is often impaired in people with depression and anxiety, which may explain why cold water swimming can act as a therapeutic tool.

Of course, it's not all clarity and euphoria. There have been rare cases temporary memory loss associated with swimming in cold waterusually occurs in older people, and it is unclear what may cause it. And of course, hypothermia is another risk factor if swimmers stay there too long. Still, I'm encouraged that the mental clarity and improved mood I feel after failures is getting some scientific backing—and, if I can keep it up, might even protect me from some age-related diseases.

Last week I heard rumors that a sauna was being built on the lakeside and I wondered what additional benefits heat therapy could bring to my swimming. I read it alternately heat and cold can cause certain changes in brain wave rhythms it may provide the most powerful brain benefits of all. But that's a topic I'll explore in a future column – testing the UK's best saunas first-hand, naturally, all in the name of science.

Until then, if you find yourself near a lake or sea this winter, be brave and dip your toe. It may be cold, but your brain will thank you.

Swimming in water temperatures below 15˚C (59˚F) should always be done with a partner, a float, a brightly colored hat and a full understanding of the potential risks and how to reduce them. Further information on water safety when sailing in cold water is available from the Royal National Lifeboat Institution. has available resources.

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