Actually I was Just thinking about this thread the past few days while commuting! (since the site was down and I couldn't chat with ya'll). I've started standing on the pedals for every steep hill I climb and am learning - you can't ride any faster than you can suck air into your lungs! As an asthmatic, if I can't get enough air into my lungs I'll start coughing and hacking! (quite pretty to listen to I'm sure) and when I have my mouth covered it helps with the asthma but it makes it even harder to suck air in. So I tailor my rides to keep those old lungs inflated and working! Just a thought!