I was looking at your site about the importance of exercise and Reasons to avoid or stop exercising:

One of the reasons to avoid exercise is if your blood oxygen saturation is below 95% and that you should always use enough oxygen to keep your level above 95%.

When I use a treadmill there is no way I can keep my oxygen level above 64% even with supplementary oxygen breathed in through my mouth and/or nose.

I would rather walk than use a boring treadmill, but do not have a portable machine, so my oxygen drops to 64% for most of the time. I am fairly sure that a pulse oxygen concentrator would not keep my oxygen level above 95% as I am forced to open my mouth to get enough breath to walk at the pace I walk.