When it finally gets cold enough in SF for me to break out the puffy north face jacket I know it's officially winter time! Starting around November and going through Mid-February I generally focus on strength exercises and those random parts of my body that get neglected but are crucial to maintaining running health. Here are videos that focus on each area:
BACK (I do these and get great results with LIGHT arm weights and leg weights):
INNER THIGHS (guys, think this is one is just for girls? You're missing out. Do some sit ups first and then go straight into these or throw some leg weights on to make it a little more challenging):
HAMSTRINGS (I think the best hamstring exercise is on the machine but do each leg separately):
If you've had issues making it to the starting line, if you have sore knees, back, IT band issues, etc it's probably due to weak muscles that are connected to or surrounding those parts. If you aren't "hip" to the benefits of strength training (sorry that was lame), it will burn fat better than running and keep those extra cookies and chocolate off your body during the holidays. This happens because while you are at rest your beat up muscles will be eating up everything they can find to rebuild. Remember though, you don't have to be huge to be strong. Think about Bruce Lee!