Breathing difficulty after exercise that seems to stretch the stomach muscles or diaphram

I don't really know where this should be posted. I think it's really abdominal muscle related. It's been happening occasionally since my late 20's. I'm 54. It is triggered by exercise (I exercise about 5 days a week) that (I think) pulls or stretches some abdominal muscles. Then about a day later I'll have trouble getting a complete breath. If I'm in bed and wake up, it'll sometimes start up and I may have to sit up straight in bed to get a full breath. This has the unfortunate effect of waking me up and then I have problems getting back to sleep. This "problem breathing" will gradually ease up over the next few days and the breathing "spells" will be fewer and fewer.  I've asked a couple of nurse practitioners about it. One said that maybe I get muscle spasms that gradually subside. Another said it could be something "as simple as a hiatal hernia, but that since I've had the condition for over 25 years, not to worry about it.

But it's a recurring problem that sporadically affects my quality of life. I try to exercise carefully but sometimes I trigger it without realizing it at the time. The latest/current episode seems to have be vigorus ridding on my recumbent bicycle. Another recent way (in the last couple of years) was vigorusly working out on the eliptical machine at the Y.  I also to workouts with the weight machines at the Y.

Does anyone have any informed ideas ?

[National Jewish Health]

It is very difficult to tell the cause of these problems (muscle, lung etc) from this description.   It is not clear if there is pain from muscle spasm or airway bronchospasm.  The best first step is to see a physician while you are having these problems to determine the cause of the problem and establish a way to prevent and treat it.