The Lauwersmeer is large and gray and mirror-like. Raindrops shatter in front of my goggles. Somewhere far in front of me someone is swimming with a purple safety buoy: a few strokes of breaststroke, then a bit of front crawl and then breaststroke again. To the left of this, the bright orange boat of the rescue brigade is bobbing.
Explaining step by step why someone swims across the Lauwersmeer on a gloomy evening is going a bit far, but the short version is this: I am one of the thousands of athletes who have started swimming in open water in recent years.
Open water swimming was already on the rise before corona, but since the first lockdown, now two years ago, the wetsuits, safety buoys and other open water swimming gear do not seem to drag on. And although hard figures are lacking (open water swimmers are often free birds, who do not join a swimming club and therefore remain out of sight of the KNZB swimming association), the trend seems to have increased considerably due to corona.
There are good explanations for the popularity of open water swimming. The closure of swimming pools during the corona crisis plays a role, as does the international success of top athletes Ferry Weertman, Sharon van Rouwendaal and of course Maarten van der Weijden. Swimming in open water also gives you a different perspective on nature. And it’s healthy.
Especially in Great Britain, where open water swimming (wild swimming) is even more popular than in the Netherlands, a striking number of swimming blogs, articles and online videos are about the effect of swimming in cold water on your resistance and especially your mental health. Swimming in cold water is said to give you inner peace.
I just don’t notice that. While in front of me the boat of the rescue brigade gets further and further out of sight, and behind me the Frisian shore changes into a thin green stripe, my head seems like an echo chamber full of disturbing thoughts. Did that sailboat see me? It’s great that the tax return is ready. How many inhabitants does Grijpskerk have and, to repeat: did that sailboat really see me? Inner peace is miles away.
In 2017, the British sports umbrella organization Swim England published a Overview in which the research available at that time into the alleged or otherwise alleged effects of swimming was examined. That report appears to be the main source of the often unequivocal claims in the popular literature, but the review’s conclusions are cautious: swimming may be associated with a reduced risk of premature death, swimming may have positive health and wellness effects for individual patients and patient groups and there seems to be emerging evidence for the physical and mental health effects of swimming. Another not unimportant conclusion of the report: research into swimming and health is rare and sporadic.
ice water guru
Claims about cold water and health remarkably often lead to the thinking of the Dutch ice water guru Wim Hof, who attributes several health effects to a combination of breathing techniques and immersion in (ice) cold water.
Matthijs Kox, affiliated with the RadboudUMC in Nijmegen, researched exactly that combination a few years agowith a striking result for skeptics of the Wim Hof method: there does indeed seem to be some effect.
Kox and his colleagues found that healthy young men trained by Hof had a less active immune system response than the untrained test group. A diminished immune response could in theory be beneficial for people with an autoimmune disease such as rheumatism.
In a comment in de Volkskrant he himself made a comment about the result: a less strong immune response is not the same as the claim that an ice bath is good for the immune system. “There’s no evidence of that.”
Moreover, the combination of breathing exercises and cold water is not without danger: Hof was discredited in 2016 when four drowning cases were attributed to his method in quick succession.
Watch out for hypothermia
“The disadvantages of swimming in cold water have been described considerably better than the possible benefits,” said Heather Massey of the University of Portsmouth. Massey is not only a researcher at the University’s Extreme Environments Laboratory, she is also a swimmer. She tells how (“Years ago, it’s a very gradual process of getting used to”) she started with very short periods of dipping in cold water. She expanded that by swimming a little further each time. In 2019 she swam solo across the Channel; in 2017 she represented Great Britain at the World Ice Swimming Championships in Germany. In presentations, she uses a photo of herself after that game, hanging over a ball line, obviously not happy. (“I stayed in the water for a while to congratulate my opponent. That was not wise.”)
‘We are getting more and more signals that swimming in cold water or open water swimming has a positive effect on your health,’ Massey says by telephone. ‘But that is mainly anecdotal and so there are serious risks involved.’
First of all, there is the cold shock – a reflex in which breathing accelerates under the sudden influence of cold water. An important danger here is that you involuntarily inhale a sip of water and drown, explains Massey.
Second, in cold water you lose control over your muscles over time. ‘And if you can’t use your limbs anymore, you can’t keep your airway clear. Simply put: your mouth and nose are submerged. And then you can drown quite easily.’
Finally, there is the risk of hypothermia – the process whereby the body temperature continues to fall below 37 degrees. ‘At 35 degrees you can already become disoriented and confused, with all the associated risks. Below 32 degrees you are in very acute danger.’
Massey mentions the four as the first identifiers of hypothermia umbles: fumbling, grumbling, stumbling and mumbling. In other words: clumsiness, moodiness, stumbling and mumbling. (Swimming and tripping don’t mix, but Massey points out that for the first 15 minutes after you get out of the water, you’ll cool down even more and can still get hypothermia.)
“As soon as you see these symptoms in yourself or someone else, you have to get out of the water immediately.”
Massey published a few years ago with colleagues about a young woman with a long history of depression. The woman wanted to stop taking her medication at all costs, after which she opted for swimming in cold water in consultation with a doctor. Successfully.
There are caveats to the article: it concerns one test subject and the woman had an explicit goal in advance: to stop her medication. In addition, halfway through the study, she became pregnant and gave birth to a child – events that seem physically and mentally more important than a daily swim.
“The anecdotal information is there. Our job now is to make sure we get better data, to see if there really is an effect. You also have to ask yourself whether it is not a bit of an extreme solution to immerse someone completely in cold water. Knowing what’s happening in the body can also help us see if there are smarter, less invasive ways to achieve the same effect. You may achieve the same effect by just dipping someone’s hands in cold water. And maybe the water doesn’t have to be that cold after all. A degree or so seems to work as well.’
Less drastic cold does indeed seem to have health effects, says Wouter van Marken Lichtenbelt, professor of ecological energetics and health at Maastricht University. His suggestion: turn the thermostat down a few degrees at home and in the office.
In recent years, Van Marken Lichtenbelt has conducted research among overweight people and diabetes patients. A slightly colder ambient temperature seemed to have a positive effect on insulin sensitivity and sugar absorption in the muscles in the participants studied, he says. “The effects of mild cold, even if it’s just an hour a day, are significant.”
Van Marken Lichtenbelt does warn against overly radical conclusions. And, he says, it doesn’t seem to be just about the cold. ‘It seems that it is precisely the alternation between warm and cold surroundings that has an effect.’
Away from the stress
‘I’m not a scientist, so maybe I’d better answer your question with poetry’, says writer, journalist and anthropologist Kirsten van Santen while she puts two cups of coffee on the kitchen table at home in Leeuwarden. Van Santen wrote the literary swimming book grab waterfor which she spoke (and swam) with the most diverse people from the Western Scheldt to North Groningen, from the nude swimming poet Piet Gerbrandy to sea swimmers wrapped in neoprene.
In the last chapter she writes about her own crossing of the inlet between Terschelling and Ameland, a swim through dangerous tidal currents, swells and waves inhaled seawater. She describes, among other things, how she vomits while swimming underwater, out of sight of the KNRM lifeboat sailing along. Not necessarily a healthy environment, she admits. But, she says with some understatement: ‘It’s a situation where you experience your body differently.’
When the coffee is finished, we walk in swimsuits to the Dokkumer Ee, where Van Santen and her neighbors have screwed a swimming ladder to the quay. (‘Illegal, so there was a lot of hassle with the municipality. The alderman came here personally.’)
With long, relaxed strokes, Van Santen goes past pompeblêden. On the edge of town and meadow, she lets herself float on the current while hanging on her swimming buoy. ‘Swimming sometimes really means swimming away somewhere. Away from the water’s edge, away from all kinds of daily stress.’
A little later, Van Santen mentions a concept from anthropology: liminality. ‘A liminal phase is a symbolic transition between two worlds. Think of initiation rituals that some peoples have. Or carnival, when all traditional roles are reversed. Or theatre, on the border between reality and fantasy.’ Water is like that, she says: a temporary world in which everything is different for a moment.
‘I don’t mean it at all religiously, or spiritually; I’m not really the type for mindfulness and I don’t like Wim Hof-like health claims, but swimming makes me feel like I’m in a magical world for a while. Perhaps it is best expressed by the Flemish poet Paul Snoek: Swimming is a bit almost sacred.’