Cold water cure: The health benefits of cold-water swimming

Submerging your body into icy depths may not sound appealing, but for devotees of cold-water therapy, the benefits greatly outweigh any short-term discomfort. Participants claim the practice—which involves plunging into or swimming in water no warmer than 15 degrees Celsius (roughly 10 degrees colder than the average pool)—leaves them invigorated and clear-headed, and even alleviates pain.

 
Ancient Greeks used water therapy to relieve fatigue and treat fever

Cold-water therapy has become more mainstream in recent years, in part due to the influence of Wim Hof, a Dutch extreme athlete who developed his own method of cold therapy coupled with conscious-breathing techniques, but it’s not a new trend. In fact, cold water has been used to promote health for more than 2,000 years: ancient Greeks used water therapy to relieve fatigue and treat fever. 

In Scandanavia and other North European countries, ice swimming is often coupled with a long sauna session. Photo credit: Jaan Künnap

In Scandinavian countries, a traditional sauna session is sometimes followed by a cold plunge. Alternating between hot and cold temperatures increases blood flow in the skin and boosts circulation. High-performance athletes also use ice baths or cold showers to help mitigate the delayed-onset muscle soreness that follows intense exercise. And recent research suggests impressive benefits for mental health and stress management. 

“Getting into cold water creates stress on the body,” says Dr. Mark Harper, an anesthesiologist based in the U.K. and Norway and the author of 2022’s Chill: The Cold Water Swim Cure. “The body reacts like it would to any stress: adrenalin and noradrenalin are released, your blood pressure and heart rate increase and your breath quickens.”

Unlike the detrimental effects of chronic stress, however, this type of wilful and controlled stress can be beneficial, according to a 2019 U.S. study published in Neuroscience and Biobehavioral Reviews. 

Apparently, combining physiological stressors, such as cold-water therapy, with focused meditation can train the brain to deal with the stress. Each time a person conquers the cold and emerges feeling invigorated, it reinforces the expectation of a positive outcome. The researchers believe that these brain changes extend beyond cold tolerance and could be applied in everyday life.

Positivity also played a part in U.K. research published in a 2020 issue of Lifestyle Medicine. The small study followed 61 people as they took a weekly cold-water swimming course over 10 weeks. At the end of the study, participants reported greater improvements in mood and well-being than the control group on shore.

Cold exposure increases “feel-good” hormones, such as serotonin and dopamine, says Harper, one of the study’s authors. Swimming is also good exercise and often a social activity, which helps to offset anxiety and allows the body to feel both pleasure and motivation.

Harper has been cold-water swimming for nearly two decades and compares the stress of cold-water therapy to that of intense exercise. “Done safely, it’s a pretty effective way to train the body,” he says. “But if you’ve got a heart condition, you have to be careful.”

Before diving straight into the sea, try simply taking a cold shower

If open water isn’t your thing, consider cold showers. A 2016 Dutch study published in the journal PLOS One found them to positively impact immunity: subjects who took a daily cold shower were 29 percent less likely to take time off work for illness.

For those wanting to try cold-water swimming in a lake or ocean, ease into it with short exposure times—just long enough for your body to get past the initial shock. Never start by plunging your entire body in at once, and always swim with a friend. Gradually increase the time you spend in cold water to three or four minutes, at least once a week. “That’s all you need to get the benefits,” says Harper.

Read more: Friluftsliv: Is this Nordic trend the key to happiness?

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