I wonder how many people are conscious of their breathing as they ride, and if so, how they breathe.

The first few weeks I started riding I was just out of breath, so there wasn't much choice but to pant. Fortunately, that soon improved. But I still didn't think much about it until I read The Art of Urban Cycling, which has a section on air pollution and its danger to cyclists. The author (Robert Hurst) recommends breathing through your nose, at least at times you are going through bad air, due to the filtering properties of the nasal passages, so I tried that. In the winter, however, my nose usually had enough problems between keeping warm and keeping clear to make this too practical.

Since it has warmed up, however, I've found that I am able to breathe in through my nose, but I still seem to want to exhale too forcefully for it all to go through there. So lately I've found a happy medium of taking in deep breaths through the nose, but exhaling through the mouth. I still mostly just do this when the air is bad, but sometimes it's relaxing to just do it for the heck of it. I'm wondering if others do the same, or something else. I suppose racers are very aware of their breathing, but I don't know how many commuters are.