Cold Water Swimming Tips

You have an early-season triathlon and need to put some open water time in. What can you do to get prepared?

I’ve been a triathlete for many years and even I dread the early season swims.  The cold water temps are never easy to deal with regardless of your experience, but there are things you can do to make your early season swims more enjoyable.

Let’s first discuss what is happening in the body when it is immersed in cold water. There are three potentially hazardous physiological responses associated with going into cold water. 

  • The first is the cold shock response (CSR), which is uncontrollable gasping, breathing, and an increase in heart rate that occurs for about 90 seconds when you first go in. 
  • The second is cooling of the nerves and muscles close to the surface of the body, particularly in the arms and legs that, when cooled enough, incapacitate you and stop you from exercising. 
  • The third is hypothermia when the body temperature falls below 35°C. This condition normally takes at least 30 minutes to happen in an adult in cold water.

Each of these responses varies in the amount of time it takes to “acclimatize” with repeated exposure to cold water. But as few as six, three-minute immersions in cold water can reduce your cold shock response by 50%. This reduction in the response to a repeated constant stimulus is called “habituation”.


So it's safe to say that planning to get into the water at least 2-3x a week is going to help. Here are some other things to consider:

  • Find a body of water that you can safely swim in.  This does not only mean location but temperature.  In Ottawa, that is usually the pond in Rockcliffe park. It is a shallow body of water that tends to be warmer than the Ottawa River or Meech Lake.
  • Never swim alone, especially in cold water.
  • Consider wearing a neoprene cap, booties, and gloves (see our store for purchase)
  • Ingest a hot beverage before entering the water to raise your internal temperature.
  • Keep the first exposure short. See the suggestion above. 
  • Have warm clothing and a hot drink ready for after the swim


All you have to do now is find a swim buddy as crazy as you, set a location/time, schedule it, and get in.


Happy Swimming!

Julia Aimers
CSEP Clinical Exercise Physiologist
CSEP High-Performance Specialist

Certified Triathlon, Cycling, Yoga and Swimming Coach
USA Cycling Level 2 Coach
Training Peaks Accredited Coach

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