The fisherman could hardly have been more surprised if the Loch Ness monster had just emerged from the water.  As I climbed out of the water and up the bank of the River Wye, the angler’s jaw went slack.  “Bloomin’ heck,” he said.  “Is it cold enough for you in there?”  The truth was it was cold in the river, about 12C, but after 10 minutes swimming my body was tingling, not shivering.  Instead of feeling cold, I felt stoked - fired up by the inner heat you get from your system cutting off the circulation to your extremities and pumping warm blood into your core.  In short, I felt alive.  Wrapped in at least four layers of clothing and preparing for a day sitting stationary on the river bank the fisherman was never going to believe me if I tried to explain how splendid cold water swimming made you feel, so instead of responding verbally, I just gave him the widest smile I could and set off to retrieve my towel and clothes.  After all I knew I would swiftly need them.  Cold water swimming is life affirming, but it has to be taken seriously.  If you don’t warm up properly after spending any amount of time in water below about 15C things can go wrong very rapidly.

For me the swim in the River Wye was a one off, an occasional treat on weekends away from London.  My daily swim takes place at the Brockwell Lido in Herne Hill.  There, instead of coming out of the water to be greeted by incredulous fishermen, you are surrounded by a community of likeminded enthusiast for open water swimming.  There is an outdoor sauna next to the pool to warm up in, and plenty of chat about the water, the swimming - and almost always - about mental health.  Time and again the conversation in the sauna reverts to one of the most important subjects of our, for that matter of any, time - our mental wellbeing.  Fuelled by the warmth and intimacy of the sauna the swimmers seem happy to open up about subjects that are usually strictly taboo.  The talk ranges from how cold water swimming has helped people fight depression, improved family relationships and increased people’s self-esteem.  This kind of reaction is not just confined to a group of people from south London.  Politicians (David Cameron is an example), actors (Nicole Kidman) and comedians (David Walliams) have all braved the cold and lived to eulogise about its benefits.

But beyond the anecdotal is there anything to the idea that cold water swimming can demonstrably help with mental health problems?  Well, clinical trials of this kind of treatment and against this kind of problem are tricky at best, but a number of brave souls have tried. Christoffer van Tulleken, a doctor and researcher at University College London, co-authored a report into the case of a 24-year-old woman with depression who was prescribed a weekly swim in cold water.  The report was highly encouraging in respect of the sole case that was studied, but could do little more than recommend further research was carried out.  The study led to a call for testimonial evidence from members of the Outdoor Swimming Society - the programme and study is ongoing.

Sadly, other than the study above, there have been very few serious studies about the positive effects of cold water immersion, meaning any benefits remain something of a mystery which are best described through anecdote than empirical evidence.  The dangers, however, have been documented.  Sudden immersion in cold water is not for everyone. The shock of the cold water and the rapid increase in heartbeat and breathing rate that flow from this can be a danger for some people with underlying health issues.  But for others - and there are an increasing number - cold water swimming is not just a way to get exercise, it is a lifestyle, an escape from the strains and stresses of modern life and possibly, just possibly, a way to tackle the demons that threaten our mental health.  

More information about outdoor swimming, the how, the where and the why can be found at the Outdoor Swimming Society website.