Two techniques for cold water acclimatization

Acclimating to cold water during an open water race is a crucial component for all open water swimmers and triathletes. That’s because the body heat loss in cold water, for a non-exercising body, can be up to two to four times greater than the heat loss in cold air at the same temperature. When you exercise in cold water, swimming for example, the heat loss from your skin can be 70 times greater than air of equal temperature.

There are two ways to lose heat during cold-water exercise, and these are due to both conduction and convection. Conductive losses are direct losses from one molecule to another through a liquid, solid or gas. Convective losses depend on how fast water (or air) moves past the body.

The body has several unfortunate responses to cold, including shivering, constricting blood vessels, increasing metabolism to use more fuel, increasing urine volume, increasing lactate production and decreasing VO2max.

All of these body responses to cold water can lead to decreased race performance in an open water race. It’s good news for all these swimmers that they can acclimatize to the cold water environment in a similar way their bodies acclimatize to heat.

Scientists have determined that there are three adaptive states to cold. The first is cold habituation, which means that a temperature that once felt cold, no longer feels cold - or as cold. The second adaptation is metabolic acclimatization. Changes to the metabolism occur that affect the type of nutrient used for body heat production or the metabolic pathway. In short, these changes may positively affect the rest of your race if your body is not burning through stored glycogen at an accelerated rate, due to cold acclimatization. Finally, for cold-water swimming events where wetsuits are not allowed, insulative acclimatization can help by changing skin blood flow or changing subcutaneous fat. These changes help maintain core temperature and reduce the body's stress response.

How to Acclimate to Cold Water

For triathletes and swimmers who compete in a non-wetsuit swimming event it might be a good idea to develop cold tolerance and the associated physiological adaptations.

Swimmers who have access to an open water situation with temperatures similar to those predicted for their event should swim in the cold water for 20 to 30 minutes, three to four times a week in the 14 to 21 days prior to the event. If it will be a wetsuit swim, they should wear a wetsuit in practice. They have to be sure to have a boat or rescue person available in case they run into trouble.

For those that do not have access to a cold body of open water, they may gain some advantage by taking cold baths. The plan is to fill the tub with cold water and get in the tub. When their body feels comfortable in the water, they can reduce the temperature by adding ice. Those using this technique have taken an ice bath for roughly 15 to 20 minutes, three times per week.

Swimmers who have used these techniques have reported increased cold tolerance and felt more confident and less stressed about the cold water conditions. If you decide to try either of these techniques, of course, use caution and monitor your body temperature all the time. If it drops below 35.5 degrees Celsius and if you feel uncomfortable or your skin turns blue or white remove yourself from the water.

Image source: [1]