It’s surprisingly hard to recover from being really chilly

I bet I haven’t let my core temperature drop more than fraction of a degree in twenty years. That is, cold enough to really get shivering — mild hypothermia. I hate that state, and I’m pretty good at avoiding it!

And apparently it’s amazingly hard to recover from. I absolutely would have assumed that hard exercise would nuke mild hypothermia, within a matter of minutes. As Alex Hutchinson explains in this piece, new evidence says “nope”: even slightly reduced core body temp is incredibly persistent: “even cycling to exhaustion isn’t enough to warm you up if you’ve lingered for long enough in temperatures around the freezing mark.”

I am very impressed by how little effect hard exercise had on those low core body temperatures. Definitely a surprising result.

The other noteworthy result here is much less counter-intuitive, but still interesting: endurance performance was strongly impaired by being chilled, even if it’s just superficial (rather than a drop in core body temperature). While athletes were able to warm up from superficial chilling much quicker, their performance was greatly reduced. A bit more from Alex, summing up:

The revelation that being really cold is bad for endurance may not seem that surprising. The most interesting distinction here, I think, is between exercising in the cold and being cold before you start exercising. One of my pathological neuroses as a runner is the fear of hearing the starting gun fire while I’m still wrestling to get my sweatpants off over my racing shoes. As a result, I often strip off my warm-ups well before the start even in sub-freezing temperatures. If there’s one idea I’ll take away from Wallace’s research, it’s that I need to invest in some tearaway pants.

This post has now been integrated into the newest addition to the PainScience.com library of articles: Whole Body Cryotherapy for Pain: The science of freezing your butt off to treat pain or enhance recovery from intense exercise.