I mentioned in a previous post on this topic that while the sea was warming up last spring I noticed an interesting phenomenah – my body felt more chilled in 22 C water than it did in 21 C. I proposed a hypothesis that there was some sort of breaker switch in my body that turned on at 21 C and activated a more aggressive conservation of heat in my core and brain, while 22 C seemed to not do this and therefore my blood circulated more freely and I got that chilled feeling almost immediately.
I was curious whether I would feel that again in the autumn as the sea got colder again. Well, in my first crossing of this temperature threshold last week, between 22 to 21 C, sure enough, I felt more comfortable immersed and cruising along at 21 C under overcast skies that I did in 22 C with sunny skies. I am still very curious at exactly what is going on inside my body!
Here is one important thing to note: it matters to my comfort a great deal at how strong the core temperature is just before I plunge in for the swim. If I am already slightly chilled getting in it will be extremely difficult to build up the fire enough to get the body to super-heat itself for the first part of the swim. My internal alarms start going off from the beginning. If it is strong when I get in I’ve bought a great deal more time in the water (without suffering) before I start to feel the chill. From what I’ve read and heard, this is the central factor of acclimatization – training the body to keep the core warm. Literally, survival, let alone comfort, depends on it.
Another question I’ve listed in my experiment: as I grow even more acclimated to cooler water this year, will my tolerance for ‘hot’ water decrease? I am wondering if our acclimatization range – what we might call our ‘comfort zone’ – stays about the same but shifts toward a cooler or warmer range, or if we can actually widen that comfort zone to include a wider range of cool and warm temperatures.
It did seem that I had less tolerance for the 29-30 C water this summer in July and August, (and naturally I was more comfortable in swim pools where my students were shivering). That hot water just sucked the energy and ambition out of me. But it could have been the hot weather, and intense overhead sun adding to that. I stayed in the cool water pockets along the sea cliffs as much as I could.
And this month I’ve abandoned my bare feet (too cold sitting at my desk writing like this) but have kept on with cold showers. Not necessarily every time but most times I use just straight cold water – depending on how strong my core temperature is. Our house doesn’t always have hot water (we have a solar water heater that has some problems) so I conveniently have no choice sometimes. And I like to be clean more than I like to stay warm so now, if I am not planning to head out for a sea swim, I have a ritual of a morning cold shower.
But in the shower also I have noticed a change in my body’s response. If the water is just ‘cool’ immediately I feel chilled by the water throughout my body. But if I let the water be ‘cold’ my skin feels the ‘burn’ of the cold water yet my core immediately feels extra warm. In this sense I am more comfortable taking a cold water shower than I do in a cool water shower. Very interesting!
Just in case someone pops in for the first time I feel like I need to keep repeating the fact that I know water above 15 C (65 F) may more accurately be regarded as ‘cool’ water and not ‘cold’ water. I am not sharing this to brag to anyone. I live in on the Mediterranean Sea so I don’t have such extremes here. And suffering is a relative thing – put a man of the tropics in the artic or vice versa and each will suffer. I, for my part, am simply taking on the project of expanding my swimming world right here where I am at. And act of eager adaptation (rather than forced). Something each person can do no matter where in the world he/she lives and with what swimming opportunities are available.
Some of you are, no doubt, far beyond me in enjoying cool, or even cold water (without wetsuit, I mean) and for quite long swims (my Channel Swimmer friends!). But I realize most swimmers rarely venture out of the safe, climate-controlled pool facilities. We see strong evidence that OW swimming is the fastest growing branch of swimming in many countries. Often, after stepping from pool to warm (or wetsuit-insulated) OW swimming, the next step is to chuck the wetsuit, and/or head for cooler water. So my observations and questions may be of interest to those of you who are likewise eager to make this liberating transition also.