The cold punches the breath out of you. Your heart slows – an automatic response to drowning. Your skin burns, crawls with a million vestigial body hairs springing to attention, then turns numb. Your bones ache. By the time you surface, you’re already screaming. But scrambling back onto the ice, you feel electric, giddy. The sub-zero wind is balmy.
That’s the 20-second sensation that seduces members of winter-swimming club Rastilan Talviuimaritry, who regularly dip into Helsinki’s frozen harbor, sometimes during lunch breaks, sometimes naked. Rastilan is not a strange splinter group; avantouinti – ice swimming – is a national tradition in Finland, and some 120,000 Finns are members of an avantouinti club. Such mass appeal is hard to fathom, and becomes only a little clearer when one enthusiast tries to explain it: “We don’t have sun – we need to be ready for the dark.”
Wherever there is ice, there have been seemingly perverse people jumping through holes in it
During Finnish winters, the sun can disappear for 51 days, leaving one in eight Finns (about 650,000 people) suffering from Seasonal Affective Disorder (SAD) – depression that avantouinti is said to relieve. But SAD is just the beginning – avantouinti is touted as a cure for everything from rheumatism to tuberculosis, and regular ice-swimming improves mood and memory, while decreasing tension, fatigue, and the symptoms of asthma.
When cold-shocked, the human body releases a whole suite of chemicals, including norepinephrine, the same neurotransmitter that gives you a kick out of playing violent computer games or taking amphetamines. Norepinephrine is the little buzz you get every time you tick an item off a to-do list, and cold water will give you a blast of it: norepinephrine levels rise 200 percent after just two minutes of cold dunking. And you never get used to the rush of winter-swimming, either. A 2008 study in the Scandinavian Journal of Clinical and Laboratory Investigation reported that cold-stimulated norepinephrine levels were “remarkably similar between exposures,” consistently rising 200 percent every time subjects took a dip through the ice.
Simply refrigerating depressed people may also work. In 2003 and 2007, Polish researcher Joanna Rymaszewska led successful experiments in “whole-body cryotherapy” for the depressed: for a few minutes at a time, recruits from the local mental hospital walked around a room chilled to between -110 and -160ºC, wearing only swimsuits, headbands, woolen socks and clogs, becoming happier.
For some people, all this science just confirms something they know instinctively. From the Spartans of Ancient Greece to Finns in the first century, all the way to New York’s “Polar Bears” jumping into the sea off Coney Island every New Year’s Day and the citizens of Harbin, China, who cut rectangular pools into the frozen Songhua River, wherever there is ice, there have been seemingly perverse people jumping through holes in it. In 1857, a patient being treated by hydrotherapy pioneer Vincent Priessnitz in Germany described feeling “so cold that we could not speak plainly,” followed by “a sensation of absolute physical pleasure... I began to think that, after all, water was my element, and that it was quite a mistake that I was not furnished... with a convenient long tail for sculling, like a tadpole.” Mariia Yrjö-Koskinen, president of the International Winter Swimming Association, puts it more plainly: “It’s like getting high, in a very healthy way.”