Another asthmatic here. haven't had major issues in years, since I moved back east from AZ where i was tethered to a nebulizer 4 times a day (in between teaching aerobics). I do notice I have to warm up well, although I don't usually do a good enough job of this. I have no trouble climbing (I mean trouble with the asthma), but I always spin up hills. The cold air does bother me, so I try to breathe in through my nose, not mouth breathe. I don't ride a lot in very cold weather, but sometimes, in the 40's it bothers me. I x country ski, and I am fine, too. I bring my ventolin inhaler with me on rides, etc, but I've only used it once. My main issue is that i get bronchitis every fall and that does me in. It goes on and off thru the winter. In 04 i had pneumonia after my tour to Vermont. I went to a pulmonary doc who gave an open ended prescription for 2 different antibiotics so i wasn't running to the dr. every week. It helped derail the cycle. I also use a homeopathic nasal rinse that really works to stop the sinus infections.