On Running, Hot Chocolate, and Why I May Exercise Outside this Winter

On Saturday, I joined thousands of other Chi-Town runners in a 9.3 mile jaunt along Lake Michigan.  Here is where we hung out before the race:

Here is me right before the start wearing a Hefty garbage bag to try to keep warm (it was 27 degrees...brrrrrr):

And here are some dudes heating up chocolate over these giant grills for the post-race fondue:

I ran almost the same course for a race in May, except it was 45 degrees warmer.  So this got me thinking about exercising in the cold.  And even though I find the cold extremely unpleasant, I may have convinced myself to suck it up and run outside all winter.  Here's what I learned from digging into the scientific literature:

1. Most people burn more calories when performing the same exercise outside in the cold versus inside or at a more comfortable temperature.  This is for a few reasons....first off, your body has to generate more heat to warm you up and it does that by burning calories.  Second...just shivering burns calories.  Third, exercising with more gear (layers of clothes, boots, hats, etc.) is more of a physical burden, which can burn more calories. 
2. How many more calories are burned in the cold is hard to find in the scientific literature.  I found one study that suggested that daily energy expenditure increased by 2% in women exercising in the cold.  That means an extra 40 calories for an average woman that burns 2,000 calories a day...that's just 2 tootsie roll midgets a day.  That hardly seems worth it!  But if you run outside 4 days a week, that's 160 calories a week and that starts to seem a bit more significant.  If you start thinking about it on a monthly basis, it gets even more attractive.
3. In general, women get colder than men and faster.  This is scientific fact, so if my HE could kindly get off my back about being cold all the time, I'd greatly appreciate it!  Women have a larger surface area for a given body weight and that makes for SHE-sicles. 
4. Women feel colder on days 14-28 of their menstrual cycle.  So if your significant other calls you "frigid" while you're PMS-ing, they are probably right!   
5. Supposedly, one can acclimatize to the cold after 10 days.  I find this hard to  believe since I still haven't acclimatized to Chicago weather after 10 years.  I think they should repeat that study in women and define "acclimation" as the "absence of violent feelings toward inanimate winter objects such as icicles, slush, and salt trucks".  Then lets see how many days/months/years/decades it takes to acclimatize to the cold!   

Now I just have to upgrade my garbage bag...and wait for the cold weather again...because today in Chicago, it was 68 degrees.