It will help you, yes. I still have to stop occasionally to catch my breath. But each time we have an exacerbation our lungs get a little worse. We have to remember that. But staying active and walking and hiking will help us and our lungs strengthen.
Many people have trouble learning to breathe with the pulse O2, the trick is to remember in through the nose and out through the mouth.

Well your numbers will drop during exertion or walking, That is normal. But shouldn't drop below 88. I find if it gets that low, I stop and take a minuet, do some pursed lipped breathing and it goes back up. Keep you oximeter with you and check it every now and then.
Oh ya start slow and don't do too much at first. It will take you some time to build up your endurance again. But it is all good exercise.

Thanks, Michael! I am going to try and get out today and experiment with my POC and see if I can make it up a hill without gasping. My at-rest O2 level is usually around 94. This, by the way, was a huge improvement after receiving an antibiotic treatment. I must have had a lung infection and didn't even realize it. All I know was that I was continually in the mid-to-low 80's, which left me tired all the time and after the antibiotic, much better! Of course, as soon as I exert myself in any way, I drop back down into the 80's, which is why I need O2 for hiking, if I can indeed do hiking again. I hope so.