  i've decided to start running ... got a pair of shoes and gone out four times in the last four days so far. thing is, i can't really run continuously so i followed the advice of some articles online and did 1 min running and 1 min walking (repeat for duration of course - about 1 1/2 miles). windchill has been about 0 deg. (Farenheit) lately so it probably won't get much worse. urlLink Here is a good article , which emphasizes not overdoing it and listening to your body. Thing is, I can't always distinguish between if I've overdone it or just merely done it! 
