A. No, never. I have found that it really messes up my calves and is not really great exercise. So no, why would I? Now, if the question is really “what do you do when it’s cold or when it’s raining and you have a run schedule”, the answer is: I go and run outside! Winter is part of life in New York City where I live, so dealing with it wearing the proper running clothes is not a big deal to make it enjoyable. And rain? Well, even though I don’t like to get my shoes wet if I can avoid that (it can takes 2 days for them to really dry out), rain is also a part of the great outdoors…and you don’t want to fear that as an impediment to running, especially as it can be raining on race day!