Ummm that sounds nuts to me...whenever I can't breathe on the test that is a sign that my muscles are too weak to do what is asked of me! Was this a full pulmonary function test? There are many different components to that.

The ones that test your muscle strength at any given time are the NIF and FVC. However they do a bunch more tests on a pulmonary function test, which is usually done in Respiratory and is done by a Respiratory therapist. You can get copies of the results of the test.