Kruse and many others around the web talk about cold-exposure being excellent for health and maybe it is. The questions I have is do we have any information about the effects of this sort of forced adaptation in people who live in tropical and sub-tropical climates? Would there be any possible benefit? If anything wouldn't someone living in Hawaii, or Phoenix, AZ be better off slowly turning down the AC and upping their heat exposure in order to push themselves to adapt to the climate they live in?
asked bypaleohacks (78467)
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on April 03, 2012
at 04:42 PM
Because Dr. Kruse is basing his recommendations on a seriously flawed evolutionary narrative, thinking that ice baths are awakening some ancient polar mammal pathway (sorry, mammals did not evolve in polar conditions and primates are even more tropical), rather than drawing on extensive literature on thermal hacking as hormesis/vascular conditioning, he is missing a key part of it, which is heat. Many of the cultures he talks about have ice baths or live in extreme cold, but they also engage in hot vaporing/sweat lodges/hot baths. The only other northern living primate, the Japanese macaque, does this as well. It's the contrast between cold and hot that will condition you the best and prevent the potentially-damaging numbness that Dr. Kruse and his followers report.
The more Southern Native Americans also engaged in sweat lodges (Temazcal) and then afterwards would bath in cold (but not freezing) cave/forest pools. I would warn that several people actually have died from sweat lodges in the past few years, so they are not something to do casually. Sauna is much less extreme. I have done Ojibwe sweatlodges with really skilled practitioners and they are a very good experience, but I've also done hot springs in Iceland, Sauna/ice baths in Sweden, Sauna/polar baths in Austria, and done Banya and Korean saunas in the US with similar benefits.
Perhaps it's not just hormesis though and has some evolutionary basis. Living out on the savanna, you would be exposed to some rapid rises and dips in temperature, though certainly not to icy levels! It's probably a very good idea to sleep in a colder room.
on April 02, 2012
at 11:22 PM
I've read (and heard confirmed recently) that cold-exposure (ice baths, freeze rooms) can affect levels or activity of "brown fat," which burns calories at a rapid rate. Brown fat is found in babies, where it is used to control body temperature in the absence of the ability to shiver. It is largely absent in adults, but still can be coaxed into action.
I don't know if this is why Kruse suggests cold-exposure, and hormesis may also be a factor, but I know others recommend it for brown fat mobilization.
on April 03, 2012
at 04:16 PM
I am not completely sure about this, but deserts can get pretty cold at night. So any desert dwellers out there? Could you conceivably get your skin temp down to 50 degrees most nights just by being outside with no cloud cover to keep heat? Such an environment may mean it is conceivable Kruse's pathway may have been turned on most nights (assuming anyone lived there) rather than seasonally.
Here is what I am getting at- if what Kruse thinks is true, and this pathway gets turned on when your skin temp is 50 degrees, well aren't there enough places on this earth where the temp falls below that during the night to justify thinking this would happen most of the time and not just during a hibernation period? Sure, humans killed it as fast as they could find fire and make clothes, but 50 degrees isn't that cold.
Anyway, it seems to work well enough to keep experimenting with it. Beware getting overzealous with ice packs. You can wear two t-shirts between you and an ice-pack and still get the skin temp below fifty.