I've been consistently running for the past 3-4 years or so. This past spring I did a half marathon and have been doing 5k's in around 25:00. I have been running actively 3-4 days per week, 3-5 miles each time. However, in the past few weeks (especially during cross country practices and intervals) I have been unable to catch my breath, yet I don't feel tired. I was doing fine earlier this year and was satisfied with my running, and I do not know what is happening for me to feel like all this progress has been for nothing? Any suggestions or breathing exercises or something so I can feel normal again?
It's possible you may have developed exercise-induced asthma, or you have allergies that are affecting your breathing. One sign of this would be wheezing. Try posting in The Med Tent. There are a couple people responding post there who may be able to give you a better answer.