My PFTs have been in the 70s for a loooong time, and that is without IVs or many abx. i think if I was willing to go on IVs they would be much higher, but right now I don't want to do that. So, by doing next to nothing (I just got a Vest in December, and HS - before I used purely inhalers and exercise) I have maintained for years - which just goes to show you can never tell with this disease. Some people do every treatment they can with religious vigor and still lose PFT %s regularly. I do think that Cf is starting to catch up with me though, which is why I have gotten a Vest and started doing treatments everyday.