On a gloomy January morning, there is a certain type of person who decides to walk in the direction of a freezing lake instead of away from it. After taking antidepressants for eight years, which she had begun at the age of seventeen, Sarah was twenty-four when she joined them. Strangely, she managed to escape the “chemical fog” by donning a wetsuit and plunging into a chilly stretch of British water.
Seeing someone deliberately choose discomfort is an odd experience. The fact that it appears to work is even stranger. The cold shock response, an ancient survival mechanism that floods the body with adrenaline and causes erratic, almost frantic breathing, is triggered during the first few seconds in cold water, according to physiologists. Anyone who has ever done this knows how hard it is to resist the urge to gasp. Nevertheless, swimmers continue to return year after year, claiming that there is something approaching peace on the other side of that panic.
| Category | Details |
|---|---|
| Practice | Cold water swimming (open water, typically below 15°C) |
| Primary claimed benefit | Reduced symptoms of anxiety and depression |
| Key researchers | Prof Mike Tipton and Dr Heather Massey, University of Portsmouth Extreme Environments Laboratory |
| Collaborating clinician | Dr Mark Harper, consultant anaesthetist, Brighton and Sussex University Hospitals |
| First documented case | Published in BMJ Case Reports on cold water immersion and depression |
| Safety guidance | Outdoor Swimming Society |
Anaesthetist Dr. Mark Harper, who has studied this for years, characterizes himself as cautiously optimistic rather than convinced. That hedge is important. Anecdotes and a single case report, rather than extensive randomized trials, make up the thin body of evidence in this case. Researchers at the University of Portsmouth’s extreme environments lab have been debating a theory known as cross-adaptation, which holds that repeatedly enduring one type of stress in this case, freezing water may cause the body to recalibrate how it responds to other types of stress, such as the daily grind of deadlines, disagreements, and bills.
It has a logic that seems almost too tidy. According to a large body of research, modern anxiety is caused by a stress response system that was developed for famines and tigers but is now triggered by unread emails and traffic jams. In the words of one clinician, “it’s not properly calibrated, and the body can’t always distinguish between a genuine threat and a mildly annoying Tuesday”. Brutal and instantaneous, cold water seems to compel a sort of recalibration. The body’s panic reaction to cold is quantifiably lessened after repeated exposure. Although many swimmers will tell you that it does, no one has been able to prove that this same softening extends to anxiety in general.
What transpires after the shock subsides is more difficult to ignore. Something changes around the two-minute mark when the skin’s temperature matches that of the water. Breathing becomes slower. The mind becomes silent, and swimmers frequently report that it stops talking for the first time in days. Individuals who engage in this behavior on a regular basis report feeling happy for hours and occasionally at ease for days afterward. It sounds almost too easy to be true, and perhaps it is in part because happiness following an unpleasant experience isn’t exactly a mystery.
Since 2006, the number of antidepressant prescriptions in Britain has more than doubled, and there is serious disagreement among medical professionals regarding how effective these medications are for all patients. This background is important. There is a feeling that people are looking for something to go along with or in place of pills, something that doesn’t have side effects or a prescription number, but it’s not that cold water swimming is being promoted as a medication substitute at least not by the researchers studying it.
After more than two years, Sarah is still swimming, not taking medication, and attending counseling sessions on her own schedule. She refers to the water more as a companion and a reliable source of solace than as a remedy. It’s difficult to ignore how frequently people who regularly swim outside use the word companion. It’s possible that the cold itself has a physiological effect. It’s highly likely that the custom of rising before the sun rises, strolling to the water with like-minded individuals, and engaging in a challenging activity before the day demands anything more of you.
This does not imply that cold water is safe. In those initial chaotic moments, the same shock response that may eventually calm the nervous system can actually be dangerous, especially for those with heart conditions or no prior experience. People who have been doing this for years have consistently advised going slowly, starting in milder cold, keeping your head above water during that initial gasp reflex, and approaching it with the same caution as you would any new, strenuous exercise.
Studies that have not yet been conducted will likely determine whether cold water swimming becomes a recognized clinical tool or remains a popular fringe practice. It currently occupies a unique space; hospital researchers are studying it because it is taken seriously enough, but no doctor would recommend it over more established treatments because it is not sufficiently proven. In between frontier medicine and folk remedies. For what it’s worth, those who are already in the water don’t appear to be waiting for the outcome.
i) https://www.bbc.co.uk/news/health-45487187
ii) https://dorsetmind.uk/embracing-the-chill-how-cold-water-supports-mental-health/
iii) https://www.psychologytoday.com/gb/blog/what-works-and-why/201901/how-cold-water-swimming-improves-stress-management
iv) https://www.anxiousminds.co.uk/cold-water-swimming-good-for-mental-health/
v) https://www.bbc.com/reel/video/p0j8zdrh/watch