Well, nowirun4fun is right.  The best way to stay in running shape is to run.  Lots of runners continue outdoors in weather comparable to Chicago.  Not in the middle of a driving snowstorm.  But the key to beating cold weather is learning to layer, get a good pair of mittens, wear a "watch cap" or a balaclava.  Schedule your runs during a warmer time of day - not first thing in the morning.  If you can't manage any of that, find a treadmill.  Where I live there are lots of clubs where you can get a monthly membership at minimal cost.  Is there a fitness center where you work, or do they have an agreement with th "Y"?  It can be done.

Len

You might be shocked to learn that you love to run in the winter!

I started running summer 2010, and was pretty scared about last winter. I didn't want to lose what I'd gained. I never wanted to have a valid excuse to not run.

So, I bought a treadmill, and I was happy to have that for nights when it got dark to early to run, or for icy days, but I found that I loved to run in the cold, and that snow wasn't much of an issue. I am still glad to have a treadmill, b/c

it is always there, my No Excuses insurance policy.

That said, the cold was NOT an issue. Footing can be, and was sometimes.

Get great clothes for running. I love UnderArmour Coldgear. Head band. Gloves. Fleece pull over. Don't go cheap. Get the best you can find. It's TOTALLY worth it.

For footing, I found a great trail that has good footing even in bad weather. There is a path that utility trucks cruise up twice a day, so there are always tire tracks in the snow to run in. It is a crushed gravel trail, so the footing is really good. Much better than asphalt, and miles ahead of sidewalks. In snowy weather, I stick mostly to rough roads (mostly gravel) or to gravel/dirt trails. Asphalt tends towards ice, and that is what is really dangerous. I also am sure to take it slow and safe if footing is sketchy. Small, short, slow steps, especially on the downhills. Ask more experienced runners for suggestions on running trails that are decent in the snow/ice, and you might find some good leads.

I loved running in the cold and snow. It was fun!

I'm not worried about this year at all.

Concerning the cold air ---

The cold air is a problem if you decide to just start running in December. But if you are running through the fall time into the winter the air temp is getting cooler and cooler through time. Your body adjusts to the colder air and it is not a shock to your lungs as it would be if you just decided to start running on a cold December day.

I hate to say it, but running is the best way to stay in running shape.  There is plenty of cold weather gear you can buy to run in to help with the brutal cold, but you just have to get out there.  Doing things like P90 will also help you with your endurance levels, so don't cut that out for sure.  Good luck to you!

  check around and see if you can find a place with an indoor track that  will allow a month to month membership.

locally, we have several-and i prefer running on an indoor track to a treadmill.

BTW- cold weather running is possibly the BEST running in my opinion- the temps really aren't the problem, but the footing can be

I will run outside regaurdless of temps untill things get too icy- then it's an indoor membership untill things clear back up- usually mid dec. untill mid march

I'm in the same boat - New England.  This is my first winter of running.  Although we have had some quite cold days, we were spoiled by an extraordinarily mild autumn so far - some trees even started budding last week.  I was in short sleeves last week and I really really hate being cold!  Give me 85 degrees any day.  This week promises to be quite chilly.  So unfortunately I think we will be going from mild to cold rather quickly without the gradual temperature drop.I have to be certain to warm up sufficiently before heading out if it's  really cold  or something will hurt when I get home.  I've spent 2 months slowed down by a calf "thing" and need to be cautious not to go out with cold muscles.  This morning it was 25 and I decided to defer my run to this afternoon when temps were more moderate in the upper 30's.  If only I didn't have an irrational fear of the treadmill.   Thanks for the motivation everyone!  It helps knowing others are braving the cold and gives me encouragement.