Comment by sigmoid10
9 hours ago
You can't get "oxygen high" from breathing normal air. The O2 levels will always stay the same unless you stop breathing for a while. What will make you feel weird in the head when breathing too fast is the reduction of CO2 in your blood.
So, if you breathe in an intensive manner for a few minutes, oxygen percentage in the blood won't change?
One a friend and I hooked ourselves up to continuous pulse oximetry and had a contest to get the lowest recorded oxygen level. We tried everything we could think of, from just holding our breath to end-expiratory breath holding to hyperventilating to clear O2 (I used to do some recreational free-diving) beforehand to exercising (jumping jacks)...
Neither of us could get it below 98%, and this was at a mile of elevation (UNMH in Albuquerque).
It is pretty easy if you use the Wim Hof method. Breathe deep and fast for a few minutes, to the point where you get dizzy or feel weird sensations. Then exhale and stop breathing while being fully relaxed. I've done this while hooked to a pulse oximeter and it takes quite a while before O2 actually starts dropping (especially because the effect can be delayed in your limbs), but once it starts you'll pretty quickly run into the regime where a normal oxi will start an alarm because O2 is too low. You can even go below 85% without losing consciousness, because your limbs will desaturate faster than your brain. It's also not uncomfortable, because rising CO2 is what causes breathing reflex, but you dropped its levels far below the threshold by hyperventilating first.
I got a pulse oximeter during COVID and was able to get my O2 levels to spike down to 64% using Wim Hof breathing (for less than a second, ofc).
If you've ever done the wim hof breathing method, it is a very intense experience.
Basically hyperventilation + long breath holds. Probably similar to what free divers do without the mammalian dive reflex due to the cold water. Or like a dangerous game kids used to do when I was in school where you hyperventilate and then have someone press on your chest until you pass out.
But anyway, I'm not sure if the science would back it up, but Wim Hof describes it as over oxygenating the blood and then stopping and letting CO2 ramp up or something. Whether it is significantly dropping the CO2 or increasing oxygen during the hyperventilation phase, isn't it kind of the same thing? Adjusting the ratio.
Anecdotally, when I was doing it regularly I seemed to not get sick at all.
No it would stay at pretty much 100% (as is normal). But co2 goes down, which lessens the ability of oxygen to come out of the blood. That's why you get dizzy when hyperventilating
Blood oxygen saturation is always near 100% in a healthy person. 95% is the low end of normal. Dropping to 90% is considered hypoxemia, and 80% is a medical emergency. So there really shouldn’t be any room to increase it significantly.
In many people a momentary drop to the 80s or even below is not an emergency or anything close to it. Not saying that it is good. Someone that is awake, sitting up, and struggling to breathe should be considered an emergency regardless of oxygen levels (and in this situation 80% would be very concerning).
EDIT: your comment is otherwise entirely correct, particularly at sea level.
90% you should really be traveling to see someone. At least an urgent care, if not an ER.
Nope. The blood is already fully saturated with oxygen (in a healthy-ish person) at rest. Even intensely breathing pure o2 can't give you a saturation higher than 100%.