I think the meter takes a reading more indicative of the O2 throughout the whole body...IOW, the oxygen/blood saturation level.
When holding your breath...you are going to feel immediate effects...but the blood is still going to be oxygenated for a few minutes...so I don't think it is possible to 'trick' the machine.
"Courage is not the abscence of fear, it is feeling afraid and doing it anyway!"
"Worrying does not empty tomorrow of its troubles...it empties today of its strength."
Corrie Ten Boom
Panic Syndrome recovery due to CBT
Post Edited (Scaredy Cat) : 5/24/2017 6:56:43 PM (GMT-6)