So here’s the deal: I’m an exercise buff, and always have been. But over the years I’ve noticed that as winter starts to approach here in the Northern hemisphere (ie, sometime around late September to mid October), my lifestyle “drive” to exercise drops significantly, and my appetite increases substantially. Almost every year I gain between 5 and 10 pounds over the winter, and it’s not discernibly correlated with holiday overeating. In fall and winter it just becomes SO much harder to exercise with the same frequency and intensity, and my daily caloric intake is MUCH harder to manage: I eat between 200 and 400 extra daily kcals, and can’t seem to help it. This happens even during periods when there is no holiday overindulgence.
Is there any research at all on whether human beings display slight tendencies towards “fattening up” (and “hibernating” vis-a-vis physical activity) for fall and winter? Could my decreased drive to exercise and heightened appetite have any ancient origins in our species?
Now, I realize that my own anecdotal case is no grounds for thinking this true of anyone else. But it does make me wonder if this has ever been observed by others and/or studied.
A further disclaimer: I can think of three other possible plausible explanations for this personal physiological observation, which might all play some role:
The aforementioned holiday overeating: Fall and winter include Halloween, Thanksgiving, Hanukkah, Christmas, New Years, etc., all of which are food-heavy customs here in the Northern hemisphere. But as I said, I’ve noticed this pattern both before and after and in between these events.
More time spent indoors: When it’s colder out, the motivation to exercise might drop accordingly, even if exposure to the cold lasts no longer than a trip to and from the car when going to the gym.
My own personal history of Seasonal Affective Disorder (SAD): This would explain both the drop in motivation and the increased eating (ostensibly for dopamine-related pleasure), but a) I haven’t experienced the affective part of this–the "winter blues–in many many years, and b) my depression is very well-managed by medication and exercise.
Any thoughts?
I’d say I experience the same thing. On a cold or rainy morning, I do feel like hibernating under those covers. A hot bath and a hot drink feel better. But I learned decades ago that I will feel guilty if I don’t get out and exercise. I try to remember how good it feels when I actually get out in the cold and get moving and again how it feels good to get home. My mantra has become, “Embrace the season.” That’s what I go with. And to soften the blow I now have a treadmill and exercise bike so there is absolutely no reason for not working out every day and mostly all day every day. If I had a tendency to be depressed, I’d never know it because the exercise gives me all the chemicals I need.
For the vast majority of the evolution of genus Homo, the species have lived in equatorial and sub-equatorial climates where the seasonal variations of temperature and solar inclinations are moderate. There are a few exceptions, such as Homo egaster in South Africa, but in general the genus hasn’t been subject to evolutionary pressure to hibernate or enter a dormant state as the American black bear and brown bear do.
That said, it is clear that physiological cycles such as energy storage, temperature modulation, and sleep rhythms change with shorter days, although given the dislocation and intermixing of human populations from different climate regions this is probably less any kind of adaptation as it is a deficiency in the human species in dealing with climate variations in high latitudes. We really still are hairless, neotonic, hunter-scavenger great apes from the savannahs which have only recently migrated to Northern Europe and the Americas, and our evolutionary conditioning reflects this.
I knew someone who grew up in Kirkenes, Norway well above the arctic circle. He told me that most of the people there slept 12 -15 hours all winter and only 4-5 in the summer. He said nothing about weight loss or gain.
My wife feels she gains weight as winter approaches and loses during the summer, but I have noticed no such tendency in myself.
I don’t know it’s not. I said it’s not discernibly correlated with holiday overeating. And as I pointed out in my OP about weight gain near the winter holidays…
So I suspect the correlation is weak, if there’s one at all. But I did admit it as a possibility.
It’s a well known psychological phenomenon. The extreme form is called Seasonal Affective Disorder, but it’s posited to exist in small forms with everyone. As Stranger on a Train says, it’s connected with the shorter days, and how our body clock resets.
Another Anecdote:
I’ve been riding my bike at least 15 miles a day, and have lost 15 lbs this fall … because I know once the snow flies, I’ll be gaining 10 of that back, and I WILL want to hibernate.
Another anecdote: I live above the 60th parallel north, so un-evolutionary, hibernation-favoring conditions abound, but I’ve always had my most intense and fruitful training sessions in the winter, from about mid-October through to early May. Little interest in going out the door, nothing to do but hit the iron at my home gym etc.