Really good questions. I look forward to seeing all the answers.
I usually just use my inhaler before I walk/exercise and again when I cannot breath any more. Sometimes I have found if I just stop, breathe deeply, slowly, don't "panic" breathe, then my lungs start functioning better. But to know how much oxygen I am getting...???? Haven't a clue!!
Also, have found...just a short time doing without proper breathing/oxygen gives me an extreme headache, which I am certain is not good and may lead to other problems. ????
Pay attention to yourselves that your hearts never become weighed down with overeating and heavy drinking and anxieties of life.óLuke 21:34.