What is extreme swimming?

Is it swimming across the English Channel? Is it a circumnavigation around Manhattan Island? Is it swimming where sharks congregate? Is it participating in International Ice Swimming Association events? However you may define extreme swimming, cold water swimming is certainly part of the equation.

For some, extreme swimming is swimming in water under 60°F without a wetsuit. For others, it is swimming under 50°F. But for an intense sub-set of extreme athletes, swimming under 40°F is an invigorating challenge.

Cold-water swimming has enthusiasts who swim year-round from Idaho to Ireland, San Francisco to Scandinavia. Stripped down to a swimsuit and swim cap, the hardy swimmers diligently head down to the shoreline to do their regular swims – as onlookers wrapped in down jackets and wool hats look on in awe.

There are organizations and competitions that cater to the lowest end of the non-neoprene spectrum. The International Ice Swimming Association conducts one-mile swims without wetsuits in water under 5°C (41°F). The World Winter Swimming Championships, held annually from Slovenia to Finland, draws competitors in races from 25 to 450 meters.

Swimmers in the Czech Republic enjoy a highly organized system, dramatically documented by Jack Bright in his film about cold water swimming (see here). “There is a feeling of anticipation and apprehension before entering cold water, followed by a feeling of joy and contentment when leaving the water. Becoming hardened (acclimated) becomes part of your everyday life.”

The willful immersion in cold water has been touted for millennia in various cultures, as a guard against colds, illnesses, allergies and diseases. Using modern science, the Czech medical community identified safe means in which people can acclimate to extreme temperatures. The recommendations include swimming for limited periods no more than three times per week in gradually colder water as summer turns to fall and winter rolls in.

Their research showed significant physiological benefits including a boost to the swimmer’s immune system, improved circulation, an endorphin high, an increased libido and an elevated calorie burn. Jack explains, “On coming down with an illness, hardened swimmers have a bigger chance of fighting it and having a speedy recovery.”

When the hardened swimmers immerse themselves in cold water, there is an initial drop of body temperature as their body attempts to conserve core heat by reducing blood flow to the extremities and outer tissues, but they are able to safely continue swimming despite a lower core body temperature. The endorphin high is reached relatively quickly, given the fact that most extreme swimmers are in the water less than 15 minutes.

The required hardening process to safely swim at 60°F (15°C), 50°F (10°C), or even 41°F (5°C), and the process to acclimatize is long and gradual. Conversely, the time it takes to lose this extreme swimming ability is quick. As a result, the hardening process becomes a lifestyle and fellow swimmers become lifelong friends.

The bulk of these extreme enthusiasts worldwide mirror the Baby Boom generation with the largest demographic group in the 35–55 year range, but some hardened swimmers continue enjoying extreme temperatures well into their 80s and 90s whether they endure the cold ocean off Melbourne or freezing rivers in Massachusetts

In the Czech Republic, there is an established time limit of 22 minutes for winter swimming and a mandatory physical check-up that includes a load test to measure heart performance. As both an incentive and safety check, there are also established performance levels in water less than 40°F: swimmers reach the third level by swimming 100 meters; the second level by completing 250 meters; the first level with a 500-meter non-stop swim; and the master level with a swim of 750 meters. Swimmers must graduate from each level before they are allowed to advance.

The optimal swimming time is 10 – 15 minutes, but even the extreme end has extremists. “In winter, the temperature of the open water drops to 32°F. Some people swim in such temperatures for up to 22 minutes,” explained Jack. “We swim up to 1K in near freezing water sometimes. There is the Czech Cup with races every weekend through the winter with rules that have been developed over 50 years.”

Even with the endorphins kicking in, there are still inherent risks in extreme swimming. Doctors, support boats, divers, ambulances and standard emergency equipment are present at these events. After extreme swimming for short periods, the cold can be felt in your hands and cold long afterwards. Many people experience awkwardness and reduced coordination when exiting the water.

Some people prefer breaststroke while others do regular freestyle. Some swim head-up freestyle to start. But, no matter how hardened you are, the cold water is still a shock. Hyperventilation and ice cream headaches are common – but part of the experience.

Proper re-warming after the swim is critical. Getting indoors, dry and dressed are your first priorities while drinking hot liquids to re-warm the body from within. Because your hands may be shivering, using a straw to drink from a cup is usually helpful.

As you venture back to shore, smiles and an inner glow are guaranteed.

Copyright © 2011 by Open Water Source