Whenever I try and wear my HR monitor to sleep, to get a good reading upon awakening, The monitor always fails to read. I've used 3 different monitors, multiple attempts - still no reading. After about 5 minutes of laying there I'll finally get a reading in the low 50's, exactly where it is whenever I've been sitting down for a few minutes. I've heard of this happening to other people, makes me wonder what's going on. (I've tried chest strap, and wrist monitors)
Anyways, to answer the OP's question, my resting HR is in the low 50's. It has been said that cardio will decrease your resting heart rate. But I doubt that it is very significant.