Nose has been bleeding lately out of one nostril (always the same one) whenever I go for runs on cold days. Cotton up the nostril before runs to help?

Dry air. Hopefully the recent rains will help. You may wish to apply a small amount of an emollient, like Vaseline, to the inside of the nostril that bleeds. It will help in keeping the lining moist and still let you breathe through that side of the nose. Do not over do the amount of emollient you apply. If it does not help you may wish to see and ENT and consider cauterization of the offending area.