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I’ve been blogging a bunch about heat (it is summer, after all), so I figured for balance I should mention this new study in the European Journal of Applied Physiology about acclimatization to cold, since it’s not a topic we hear about much. Researchers at Kent State compared five “cold-weather athletes” with eight controls matched for fitness, physical activity, size, etc., in a graded cycling test to exhaustion at 5 C. The result: the cold-weather athletes were more efficient than the controls:
Specifically, [cold-weather athletes] had ~20–30% lower VO2 at submaximal workloads, compared to [non-cold-weather athletes].
Cool, huh. So what’s going on here? Well, they don’t really know. When we talk about heat, we know there are specific physiological changes that occur with acclimatization, like increased sweat rate and blood flow to the skin. The researchers suggest that it’s “possible” that cold-weather athletes were “more able to buffer lactate at a given workload due to their experience with exercising in cold ambients,” though it’s not clear to me why that would be.
Another point worth mentioning is that the cold-weather athletes were actually football players, and their cold-weather exposure consisted of about 10 hours a week of winter practices in temperatures hovering around freezing. Morever, they were special teams players (punters, kickers, long snappers), “so it follows that they did not acquire as much activity as other athletes on the football team (i.e., only 20–30 min per practice were spent doing kicking drills and the rest of the time involved mainly standing or sitting in the cold).”
Oh. So these were not speed skaters or something. So I’m not convinced that there was any serious cold acclimatization. And as far as I can tell, the study didn’t have a control trial to make sure that the football players weren’t just more efficient (from better training) than the controls under all conditions. (They did a familiarization trial at room temperature, but didn’t analyze the results). All in all, I think the only thing we can conclude from this study is that “cold acclimatization” is an interesting concept that doesn’t get enough attention and merits further study.
After running all winter and spring in the Edmonton winter I always find the first few warm runs of the year to be terribly difficult. It’s like my body forgets how to thermoregulate in the other direction after the winter.
Yeah, the control group definitely seems like a problem. If you measured performance of a set of athletes in warm conditions, and then sent a portion of that group to train in cold weather for a period of time, and then measured them again that would seem more reasonable. But a study like that is obviously more costly too. I think you would also want to control how they manage the temperature through clothing. In my experience, people who exercise in cold temperatures regularly are more adept at knowing when to add and remove layers, and that can have a huge impact on performance too. Interesting post, thanks.
As someone who conducts her (anthropological) research in the Arctic, I’m thrilled to see studies about cold adaptation on Sweat Science 🙂 But is 5C really “cold”?
Yeah, I was unimpressed with the “coldness” of the temperatures too. Heck, it was that cold on my run this morning — and I’m in Sydney right now! 🙂
Mike, just wanted to point out that the study did control the clothing worn by the subjects in both groups, so they were equivalently covered.
Josh: it’s definitely expected that the first warm runs of the year will be hard. There are real physiological changes that take place after a week or two of training in the heat (higher sweat rate, greater blood flow to the skin) that allow you to handle heat better. Whether the opposite happens in cold weather (i.e. whether your body makes changes that allow you to exercise more comfortably without freezing your butt) isn’t clear — and unfortunately, this study doesn’t really clear things up.