When cold water becomes therapy: the Danish addiction to winter swimming

CopenhagenBirgitte Thorup Nielsen (67 years old) carefully descends the icy stairs to avoid slipping. The sea water is -1 degree Celsius, and the strong wind whips up waves that splash her swimsuit before she enters the water. On a winter morning, the sun is hidden behind a gray sky, and the air temperature is -4 degrees Celsius, but the gusts of wind make the cold feel even more intense.

When Birgitte submerges herself in the water, she inhales slowly through her nose and exhales even more slowly to stay calm. The bath lasts only a few minutes, as the cold is particularly harsh today. However, she assures us: "The cold water revives me; there's no better way to start the day."

For the past 10 years, Birgitte has repeated this ritual every Sunday, and like her, more and more people in Denmark are heading to the beaches and lakes during the winter to experience the effects of the cold water on their bodies. Especially since the Covid-19 pandemic, winter swimming has become a very popular activity in the Nordic country, something that can be easily seen by simply strolling along the bathing areas of Copenhagen on a weekend, even in February.

The Danish Winter Swimmers Association confirms that membership has doubled in recent years, to the point that most swimming clubs in the capital can no longer accept new members and have waiting lists of up to 10 years. According to a study by the University of Southern Denmark, one in thirteen adults swims in winter, while among young people aged 15 to 29, the figure is one in ten. Those who plunge into the icy waters say they do so to improve their health, as scientific studies describe how people who swim in winter experience less pain, less depression, and generally greater well-being.

Cold therapy

The growing popularity of winter bathing has led scientists in recent years to begin investigating its benefits, although this is still a field of research with much ground to cover. Dr. Susana Sølberg, in her book Hop and havet [Jump into the Sea] asserts that being in contact with the sea year-round is a blessing for both body and mind. Søberg explains that the body's physiological response to the cold is to adapt to extreme temperatures, which triggers certain beneficial hormonal and metabolic responses, preventing diseases such as obesity and diabetes.

A study conducted in collaboration between the Novo Nordisk Foundation and the University of Copenhagen, and led by Sølberg, indicates a connection between winter swimming and the activation of brown fat in the body. Swimming in cold water increases calorie burning and reduces blood sugar levels. From a psychological perspective, Sølberg argues that exposing the body to cold water releases endorphins in the brain, which relieve pain and produce a surge of hormones like dopamine and oxytocin, associated with a feeling of well-being that swimmers may experience.

For many winter swimmers, it's difficult to describe the sensation of plunging into cold water, but for researcher Elisabeth B. Østergaard, it's the closest thing to switching off your brain: "The brain simply doesn't function because it goes into survival mode when you're in a very cold environment," she says. The result, "is an instant feeling of peace of mind that helps combat stress, as you become much more aware of your body. This feeling carries over into the rest of the day and can usually be applied to your daily life," the researcher says.

Another benefit that many swimmers describe is the sense of accomplishment from overcoming the cold water, which boosts self-confidence and helps you tackle even the most challenging situations, says Østergaard. An added factor is that many bathing clubs have mixed changing rooms shared by men and women, and nudism is a common practice while swimming: "This fosters a more relaxed relationship with your own body, since you're surrounded by other people with normal body types," the researcher states. Finally, nature also plays a significant role, because "being immersed in seawater gives you a feeling of being part of a much larger environment and provides relaxation and a sense of security," the expert explains.

"A life-changing experience"

For those wanting to experience these benefits and sensations for the first time, Stella Giovanna guides new members of the Skovshoved Havbad Club, located north of the Danish capital, to ensure a pleasant experience entering the icy water. Giovanna has been practicing winter swimming for 15 years and also leads sessions of saunassince it is very common for bathing clubs to have saunas to exchange the shock of cold with heat.

Winter swimming isn't recommended for pregnant women or people with heart conditions, but beyond that, "people of all ages come to the club," says Giovanna. To get used to swimming in the cold, "it's best to gradually acclimate your body, starting in the summer and continuing regularly until the colder months of the year, not doing it suddenly," she says. Another piece of advice is "never swim alone, and look out for each other, especially on the coldest days," she states. Beyond that, "I recommend calm and concentration," says Giovanna, "and if I see someone starting to hyperventilate, I tell them to take a few deep breaths, exhale slowly, and calm down."

Before moving to Copenhagen, English writer and journalist Laura Hall could never have imagined that winter swimming would change her life. Hall explains that the neighborhood in the Danish capital where she lives "is like a seaside town, where I always see people in the water swimming, boating, or with paddleboardingBut what surprised her most, Hall says, was seeing people she "considered crazy," she says, "to bathe year-round, often naked, and then get dressed to go to work."

Hall went through a period of burnout when she "couldn't sleep, I was stressed" until she quit her job. "Suddenly, I had a lot of time, and the doctor recommended I spend more time in nature," she recalls. That's how Hall started swimming: "After the first time in cold water, I discovered that my body felt like a switch had been flipped; I was bursting with energy. It's the most addictive feeling I can imagine," she says.

That's why Hall repeated it every week for a year, which led him to swim in such unimaginable places as an Arctic fjord in Norway, a spa A nudist beach in Sweden, a volcanic beach in Iceland, and even Greenland: "Where I was surprised that the water was so clear and icebergs were floating by." The journalist has written a book about this experience, published in English. The Year I laid my head in water [The year I put my head underwater] where he explains his research to improve the quality of life by swimming around every corner of Scandinavia.

Laura Hall also admits that winter swimming has changed her personality: "Swimming in the middle of winter pushed me out of my comfort zone; it's been incredible." The writer recommends swimming in cold water at least once a week "to do something that really scares you, but that pushes you to do other things you wouldn't do in your daily life, and that makes you feel more confident." "I don't swim in winter because I want to swim; I swim in winter to feel how I feel when I get out of the water," Hall says.

In this respect, "Copenhagen is the best city in the world for swimming," he believes. In the 1990s, no one would have swum in the Scandinavian city's canals and harbor, as they housed shipyards and other heavy industry. But in recent decades, the industry has left, and the neighborhoods near the sea have been revitalized, making waterfront areas a central urban feature. Dozens of swimming areas have been created, allowing people to swim right in the heart of the city: "The water is really clean, and swimming in the sea is part of everyday life for residents," says Hall. The city council has also created a website where you can check the water quality at any time, and even the ferries, which operate like buses, use green energy instead of fuel, all to keep the water clean. "It's fantastic. I would recommend that everyone who comes to Copenhagen not forget their swimsuit and try to go for a swim," Hall concludes.