danielg1 may be on to something. I was diagnosed with exercise induced asthma this past spring. (about 10% of the US Olympic team has asthma by the way) Although I have been a casual runner for years, it didn't really make itself known until I increased my runs to more than an hour at the same time increasing speed. The treatment is pretty straight forward by using an inhaler containing a prescibed drug Albuterol 30 min before a run. As long as I am dosed, I am good to go and good as new (that is for a 47 year old)

What I haven't solved is how to handle really long runs. The medication poops out at about 3 hours. So far trying to redose on the run doesn't seem to work - any suggestions?

I have asthma as the result of a case of bronchitis a few years ago. I take singulair 1x day and use advair inhaler daily. I do OK about half the year; I usually have trouble in the spring, and again August-October, when the weather is changing and the fronts come in. I've found on my long runs that I can just use the Albuterol inhaler before my run and then again during it. It's probably not going to last more than 2-3 hours when you're running. It must be OK to use it more frequently because when I have an attack at home I've had to use it four or six times. You get a nice case of shakes but it passes.

I have 'cough variant' asthma which means I really don't wheeze, just cough. I just go ahead and run anyway because I can't find out anything else to do. If it's bad, I walk for a minute or two, and I try to run with a count in my head, for example, breathe in two strides, out two strides and pace it. One problem with asthma, too, is a difficulty with exhale (altho the perceived problem is inhaling, like you can't get enough air) so if you are feeling a little breathless try a good strong exhale first.

So, my times drop a couple minutes a mile? I'm still running! Doing my first marathon in December!
HAPPY TRAILS!!! Let me know how you do!
Chikin Biskit