It’s common knowledge that a diver who ascends too quickly from a dive can easily experience decompression sickness (a.k.a. the bends). Without going into a lengthy technical explanation, the basic cause for this is that the diver simply did not allow his or her body to reacclimate slowly and gradually. Instead, the sudden change in the external environment prompted a drastic and unpleasant physiological response.
A similar situation holds true for colder water swimming – as I had the honor of experiencing on Sunday…
Prior to swimming in colder water, one of the most effective things you can do is to “prime” your body in advance through a progressive exposure to colder temperatures. I typically recommend a pre-swim shower that starts out lukewarm and gradually tapers down to much colder levels. This “ramping down” allows your body to acclimate very quickly to colder swim environments because it directs blood flow to your core (i.e. your head and torso). And as long as you are properly geared up, you can swim in very cold waters quite comfortably.
As soon as you exit the water, though, you have to manage things in reverse – with one slight twist. First of all, your most immediate post-swim challenge will be managing the afterdrop. This translates to getting and keeping heat in your head and torso and forgetting about your numb and white-tipped hands and feet for a while. In fact, as the afterdrop lowers your core body temperature, your body will “suck away” even more heat from your extremities in the short term.
What all this means is that you will arrive home with very cold and pale extremities that need to be warmed up in the most effective manner. And just like with decompression sickness, if you make any quick changes in your physiological state you will be punished unmercifully by your own body. So here are the steps:
1. Keep all your swim gear on (wetsuit, diver’s hood, etc.) but remove your gloves and booties.
2. Step into the shower and turn on the cold water (very important!)
3. Spray the colder water on your face, hands, and feet for several minutes (believe it or not, this will actually feel good).
4. Gradually increase the water temperature to warmer levels and then start shedding your thermo gear and warming up the rest of your body.
I goofed big time last Sunday when I jumped in the shower and immediately trained some very warm water onto my hands and feet. Because the blood vessels in my outer extremities were still so constricted at that point, the sudden temperature changes were too much of a shock to my system.
And instead of getting some quick warmth and comfort, I experienced excruciating pain in my hands and feet.
When I finally had the sense to turn down the water temperature to cold, the pain went away immediately. And, as I mentioned above, the sensations of colder water were not at all unpleasant on my extremities.
The key takeway here is to realize that your body does not work like an “on/off” switch. It is wonderfully adaptive, but you need to go by its pace – and not by yours. So make sure you “ramp up” at the tail end of your swim workout in much the same way that you “ramped down” in the hour prior to your swim. Because if you push your body too hard, it will push back!