asthmatics...

I have asthma and have complete the C25K. I use a preventative inhaler every morning, and prior to my running, I do a couple of puffs on my "emergency" inhaler (pro-air) Get's me through it without any wheezing

I don't know how bad your asthma is, mine is pretty mild, my doctor recommended that I use my rescue inhaler before any strenuous runs, or if it is windy out, or on high pollen days. I would consult your doctor on this one, especially if it was as bad as it sounds.

I wrote a blog on here about running with asthma. I will preface this by saying that as of now I've only had 2 non-exercise induced attacks, and I have the cough variant asthma. Regardless, the process should be similar (the limits may just be different). I also take 2 puffs of ProAir prior to exercise. On top of that, I spent a lot of time just walking, working on breathing patterns, and getting to know my triggers. I have a severe allergy to grass (to the point that I went into shock during my scratch test), so I know to avoid running on hot, dry, windy days. I also know that hills can trigger attacks - I've learned that this is mostly because my breathing pattern changes when I run them. I've spent extra time taking hills slowly and focusing on my breathing while walking and then jogging and then running hills - now I can run up them without an attack. I've also learned that no matter how much I train and how much I learn strategies to run with asthma, I may still have an attack and need to cut my run short. I think that was the hardest part. Not giving up after one bad day. I had to stop comparing myself to others and even to myself and what I did the day before. With asthma, a trigger may be present one day and gone the next. I think the best advice I can give you is to take your time, slow down, get to know your body, and celebrate each success no matter how small. Best of luck to you!