I'm dealing with this myself. I've had asthma almost as long as I can remember. I take Advair, Singulair, Spiriva, and albuterol, prednisone and allergy meds (Xyzal + flonase), but the hills kick my tail (and like Onix, not doing hills is not an option).

I've started trying to just spin up hills and keep my breathing even. I've noticed when I start climbing hard, my heart rate goes way up and I start breathing sporadically. I think I sometimes have a mini-panic when that happens and my breathing can get really bad really fast.

If I focus more on a slower pace and sit up a little bit to open up my chest (relax) and then concentrate on breathing in through the nose, out through the mouth I do better. It still sucks.

I'm interested to hear any other tips.

Onix--if you dont' see a specialist for your asthma, you should. I'm on the hunt for a new pulmonologist, but asthma/allergy specialists can be good as well. They're better equipped than most GPs to deal with this stuff and are on top of the latest/greatest.