Even I, the inveterate outdoor exerciser, almost didn't head outside last week. The weather on Tuesday was bitter, the wind chill worse (4 degrees, I seem to recall) and the house warm and toasty. But I did, living to tell the tale and to do it again the next day, and the next. It wasn't easy and it wasn't particularly fun, but it was, ultimately, satisfying. Here are five benefits I gleaned:For non-fashion-conscious me, matching doesn't matter anyway.