Thank you all so much for your welcome and supportive comments
'Burstcouch' mentioned making sure my Doc knows about this and April 61 mentioned interest in any results re lung capacity. I am seeing my consultant next Monday so will mention it to him - I know there will be no problem as it can only benefit me, but best to make it 'official' I guess.
As regards lung 'capacity' that is already huge but useless, my lungs already being oversized and floppy, stretched and hanging below the lower rib line - with the diaphragm also floppy and 'dropped' compared to normal. This makes the in - out breathing harder and more 'conscious' than it should be. The oxygen (02) problem is due to destruction of my alveoli - this cannot be reversed. Air trapping too is a major part of COPD - we get the air in, but as we breathe out the small airways tend to collapse, trapping air and causing 'hyperinflation' - the cause of those over stretched floppy lungs. This will be my biggest enemy as the further / faster I walk , the more air trapping until I am breathing from very little capacity left at the top of the lung. Much of this 'deflates' in the hour or so folowing exercise. Added to that we have muscle loss and wasting - with the loss of type 2? fibres - I think the perceived wisdom is that even when muscle strength is gained, we still have muscle endurance problems.
So, why do it you might ask. Well there are great benefits. A couple of weeks inactivity for COPDers = 16% loss of muscle mass - and the less muscle the poorer oxygen use and fewer 'mitochondria' for energy production. So all exercise is good. Walking is considered the best exercise of all for COPD and finally - I have read research papers stating that serious regular exercise can extend our (copd'ers) life by an average of 7 years. As we have no cure and much shortened lifespan that makes it the best medicine of all Mostly - this is not a certainty - I just might build enough more muscle and increased capillary mass to be able to manage without 02 again for a while at least That would really be something!
So - today I stuck with my 1 mile 'shuffle'. I am afraid it took 1 hour 40 minutes of real hard slog, not my best time - but I will improve - you will see! Best wishes Parvati currently 'deflating'! PS sorry for long explanation!