I don't know if the road to Heck is paved with good intentions, but I do know that my pledge to make healthier life choices and wear a mask when commuting by bike in San Francisco hit a major pot hole soon after I started. The first mask I tried was the Moldex AirWave respirator mask. While it was comfortable on my face, and I felt like it created a good seal, once I started breathing hard, it got pretty hot in there. Even thought it wasn't difficult to draw a breath, once I let the breath out, it made my face steamy. With the heat came the sweat, and with the sweat came my eczema. The AirWave mask made it about three miles before I had to take it off. I'm trying to look good by riding my bike! A bout of eczema really doesn't help with that. Next day at work I picked up the Moldex 2300 Particulate Respirator - N95. The N-part means that this mask is not oil-resistant, and the 95 refers to the percentage of particles 3 microns and larger that are blocked by this mask. 95% is pretty good. The reason I thought this might work better is the Moldex 2300 has a vent on the front of the mask. When I breath in, I pull air through the fabric layers of the mask filtering the bad particles in the air. When I breath out, the vent opens and gives my exhaled air somewhere to go. Here's where I'm tempted to say that the 2300 worked great and I wear it every day now. But the truth is, wearing a mask - even one as cool as the 2300 - is just not as comfortable as feeling the wind on my face as I zoom through town. So I have come to terms with the fact that I'm breathing in some not-too-wonderful stuff while I'm riding, but at least I'm still getting some exercises. If I try other masks for biking, I'll keep you posted if they work better for me. But for now, I'm just riding without a mask. One thing I've learned is it's probably a good idea for anybody with a medical condition to talk to their doctor before donning a mask while exercising. Just so you don't think I'm giving up on safety, I have added one other piece of protection to my gear. The other day a bug hit me in the eye. Now I wear my impact-resistant safety glasses from Pyramex. I like the Goliath model because they look like regular cool sunglasses - and they are! - but they also meet all ANSI Z87.1-2003 High Impact requirements. Those bugs don't stand a chance.