Hi - I'm new to this forum. But, i have run (pardon the pun) into a some breathing issues that have simply shaken my confidence in my ability to run. I have been running for almost 20 years. Prior to about 5 years ago, I could typically run comfortably at an 8:45 - 9:00 mile without too much effort. My best half was 1:50 in 2009. However, not long after that, I slowly started experiencing breathing difficulty periodically and would have to stop for a few seconds and catch my breath. It only got worse over time and eventually, the 9 min pace slowed dramatically to over 10-10:30 ,and I would have to walk for at least 30 seconds before I could start up again. Sooo... after many visits to cardologists & pulmonologists.. there's nothing wrong with my heart or lung function.. (which I'm very relieved about!!) What it has revealed is that allergens in the air have caused upper respiratory asthma, mostly related to tree pollen and mold here in Tennessee. (lots of it, I might add) ..So now, I'm on a regular of allergy shots and have been for about 5 months. I was hoping that the shots would improve my running pace, but so far, not so much. I am seeing some improvement in other facets (like stair climbing) but, the running pace is dreadfully slow (11:30) and I can only maintain something faster for about 2 minutes & then I have to walk again. Has anyone experienced this and if so, what was the remedy / length of time for allowing the allergy shots to fully kick in?