Winter officially starts on Dec. 21, but if you’re feeling adventurous there’s no reason to head indoors. All you need is some solid cold weather running gear and you’ll be set for some fun winter runs.Thick fleece-lined running tights. I’ve tried $100 tights and $30 tights and as long as they’re thick and warm, I’m not picky.A running balaclava. You know those one-piece head covers with eye and mouth holes. This covers everything on top.Gloves. Most good pairs will be thick enough to …