What is extreme swimming? Is it swimming across the English Channel? A circumnavigation around Manhattan Island? Swimming where sharks congregate?
However extreme swimming is defined, cold water swimming is certainly part of the equation. For some, extreme swimming is swimming in water under 60 degrees F without a wetsuit. For others, it is swimming under 50 degrees. But for an intense sub-set of extreme athletes, swimming under 40 degrees 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 41 degrees. 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 page 2 to watch the trailer). "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 centuries 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. Bright 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 in cold water is long and gradual. The time it takes to lose this extreme swimming ability, however, 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-to-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.