Cold Water Swimming Tips

Post IMCDA practice swim 2012

Swimming in cold water can be anxiety provoking, after all, its not normal to jump into 55 degree (12.7 C for all of my metric system friends) water WILLINGLY!!! Many times in Ironman or half-Ironman races, we are faced with this exact situation, it's never comfortable. However, with a little physiologic understanding, preparation, and having the right equipment, we can give ourselves the best opportunity to be successful and can make a world of difference in our perception of cold water racing.

Preparing for cold water is important because it can effect not only the acute swimming portion of a triathlon, but downstream on the bike it can make a big difference....and if we can curb our natural physiological responses to keep us warm, we can also save some energy.

This morning, Kate, Guy and I took a dip in Couer d'Alene Lake at the swim start. This was a key session in the preparation for Sunday's swim. It helped me set expectations, dial in how long I need for my body to acclimate appropriately and give me an opportunity to make sure the gear I have is appropriate and functioning properly. But first, here is a little science to give background.

Hypothermia is defined as body core temperature dropping below 95.0 F (35.0 C). Typically normal body temps are around 98.6 F (37.0 C) with some variation on both sides of the "coin." When the core body temp begins to drop, our sympathetic nervous system kicks in and we physiologically begin making changes to preserve our normal body temp such as shivering (increase heat production), vasoconstriction of surface blood vessels (decrease the amount of heat loss), tachycardia (increased HR), and tachypnea (increase breathing rate as a result of initial increase in metabolism) all in an attempt to maintain homeostasis or normal thermoregualation.  All of these responses make it difficult when we are trying to perform, not survive!

Also, many times when we swim in cold environments we experience vertigo (dizziness) and/or imbalance. Many times nausea can be present as well. This phenomenon is well known in the medical world, also known as the Cold Caloric Test. This test is used by physicians to test our vestibular-ocular reflex, in laymen's term, the caloric test is good at assessing the integrity of the brain stem. In short, our brainstem is a very important part of the brain as the nerve connections of the motor and sensory systems pass through brainstem, therefore, if it isn't functioning, WE AREN'T FUNCTIONING!! (this test is used mostly in the unconscious patient to test brainstem function) One part of the test places cold water into the external ear canal. As a result, an intact brainstem causes the feeling of vertigo. So in essense, when we jump in a cold lake, we are eliciting the normal response of a cold caloric test.....for 2.4 miles!!

As I have belabored the point enough, what does this come down to?? Having the right equipment for cold water swimming decreases the normal aforementioned symptoms that cold water will induce and hopefully help improve your chances for a better swim in suboptimal conditions.

For the swim at Iroman Couer d'Alene, I will have the following:

1.) Full wetsuit (Blue Seventy Helix)

•  A full "wetty" facilitates in preservation of core temp by minimizing shivering and initial, anxiety provoking shock. We can lose a significant amount of heat to radiant heat loss at our skin. 

2.) Thermal Skull Cap (Blue Seventy makes one with wool on the inside)

• Remember, when the body is exposed to cold water, our peripheral blood vessel constrict, in an attempt decrease heat loss. This does not happen to our cerebral bloodflow. As our blood pressure rises as a result of increase HR, more blood is pumped through the carotid and vertebral arteries and we can lose up to 50% of our body heat through our head.  Cover the "noggin."

3.) Neoprene Swim Socks

• In cold water survival situations, our feet don't really matter, but remember we are participating in a triathlon and the bike is next. Therefore, escaping numb feet after an hour is a nice luxury....nothing like riding the first hour of the bike on "stumps" because you can't feel your feet. 

4.) Ear Plugs

• Remember that cold caloric test, if no water gets into the external ear canal, no dizziness, imbalance or nausea.

Next time your are prepping for a cold water swim race , try these few easy "tricks" of the trade and overcome your normal physiologic response! 

Swim fast,

Crazy J

These are just opinions of mine and in no way do I claim to be an expert in hypothermia, these are tips from my experience.