<P>The FEV1 is part of the PFT's, is tells how good the small airways are I believe. Mine is running at 31%. Still able to do a 16 min. mile for 2 miles on treadmill with grade of 4.5, heart rate 130. Exercise is the way! I use O2 with demand flow only for the treadmill.</P>
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<P>It is...