Swimming the Seven Seas: Cold Water Acclimation

Now that its Fall, its that time of year for cold water acclimation. This is my first year for fall cold water acclimation training. Unfortunately, I didn’t do too much of it before my channel swim, and it wasn’t until my qualifying swim in Boston one month ahead of time that I realized it was something I REALLY needed to work on. At that time of year, my only option in Indiana was taking ice baths and eating lots of food for weight gain, then I flew out to England a week and a half in advance to swim in the channel everyday before my swim. The latter is what I believe made the biggest difference.

There are two aspects of cold water acclimation. Physical and mental acclimation. Physical acclimation requires training your body to learn how to generate the needed heat for extended exposure and how to distribute the blood flow. For example, other than the head (which is somewhat protected by a swim cap), the majority of body heat will be lost through the extremities, the arms and the legs. The reality is that there is less body fat on the arms and the legs than there is on the core of the body, so the blood vessels are closer to the skin and result in greater heat loss. A well-acclimated swimmer’s body learns how to restrict flow to the arms and the legs and draw it in towards the core, thereby reducing heat loss. There are side effects to this: numbness in the hands and the feet and what we call “claw hand” where the fingers start to curl up and stiffen. In extreme temperatures or periods of exposure, the lack of circulation can lead to nerve damage. However unseemly these side effects are, they are still preferred over hypothermia, which can lead to mental slowing, organ failure……….and even death.

Mental acclimation involves training yourself to think in terms of survival, not comfort. No, 60 degree water will never feel comfortable for just about anyone, even someone who swims in even colder water. During my channel swim I shivered the entire time, and the next day my jaw hurt because I was clenching my teeth for 10 ½ hours. This is extremely uncomfortable, however it was different than my qualifying swim the month before where I experienced abdominal spasms. Just like any of the million other things to feel uncomfortable about in open water: swimming in the dark, marine life, salt water, chaffing, etc. it is just something you have to do over and over again until you learn what is cold and what is dangerous; what needs to be attended to and what just needs some extra mental toughness.

So the month of October has been cold-water acclimation training for a few members of my training group, the Morse Posse (more on them in later blog posts). My number one partner in crime has been Victoria, who is just as much of a freak as I am. Dr. Tom and Will (swam the channel earlier this year) have also joined us for a swim or two each. Dick, who owns the property and dock that we push off from, followed us last weekend in the pontoon during our coldest swim to date, and my husband Morgan, my sister Calley, and Victoria’s husband Herman have kayaked for us a couple of times. As you can see this is a team effort! Cold water swimming (and open water swimming in general) should not be done alone. One thing that has helped us is that we have been swimming regularly all summer, so we have been riding the water temperature downward instead of just waking up one morning and deciding to go for a cold water swim. Last weekend was our coldest swim to date with the water at 52F, the air at 33F, and we swam 5k in just over an hour. Victoria, Will, and I started having second thoughts when Dick threw a snowball at us made from frost on the boat, but that’s the beauty of a training group. Once you commit you have to at least try at that point.

So, you might be wondering, how have I been doing? I have been doing remarkably well, considering my poor performance in June of last year. While entering the water can be rough with extreme headaches at the base of my skull and difficulty catching my breath, after I get going I feel pretty good. I have yet to even start shivering during my swims (none of our cold water swims have lasted longer than 2 hours, and the coldest swims have been around 1 hour) absolutely no spasming, and no signs of hypothermia. In fact, I have noticed my feet and hands going numb while my core stays comfortably warm which is a very good sign. My mouth also goes numb (it’s the first thing to go for me), causing me to slur my words, and last weekend my tongue went numb as well as a result of the freezing air temperature and breathing through an open mouth for an hour. Today at the lake we stopped for a minute or so at the beach to regroup and I stood up in waist deep water. Once I started swimming again, I noticed how cold the water felt on my chest, meaning that my body managed to bump up the heat in that short amount of time to where my chest started to felt warm…….even though it was partially exposed and wet in 42F air temperature. I get cold in my 68 degree apartment, so this was a total breakthrough for me. After our swims I feel alert (no mental slowing) and each time I have started shivering after I get my suit off and my clothes on and I’m putting on my socks. The shivering has been moderate and lasts about an hour. After about 2 or 3 hours I start to feel warm (although if I dry my hair with a hair dryer I feel warm much sooner). The symptoms have not gotten much worse as the temperature plummets meaning I truly am acclimating to this. At this point, having swam in 52, maybe 60 would feel balmy to me!

Just as a sidenote, I wanted to mention that cold water is a weight loss secret. Shivering uses so many tiny muscles that a person swimming in cold water burns about 3 times as many calories as someone who swims in warm water. Channel swimmers tend to burn about 10 lbs during their swim, even though they are continuously taking in high caloric drinks and snacks. Just something to chew on.

Here are some photos Dick took last weekend at our coldest swim to date. Hopefully the water stays above 50 for at least another weekend so that we can do a Halloween swim. I even have a costume in mind.

Frost on the boat