[nradov]

I don't use any particular breathing technique and my blood oxygen saturation is typically very close to 100%, just like most other people without lung disease. If you're getting benefits from breath work then that's great, but it's not because of oxygen levels.

[blurbleblurble]

Good point! I was thinking in terms of oxygen/CO2 balance. But strictly speaking, I realize your right in that hyperventilating won't actually increase absolute oxygen levels.

[jules]

If this is the case, what causes the light-headedness when you hyperventilate?

[goldenkey]

"Low carbon dioxide levels lead to narrowing of the blood vessels that supply blood to the brain. This reduction in blood supply to the brain leads to symptoms like lightheadedness and tingling in the fingers. Severe hyperventilation can lead to loss of consciousness. For some people, hyperventilation is rare."

[blurbleblurble]

I understand the tingling of the fingers to be caused by a reduction of calcium ionization:

"Low levels of carbon dioxide cause tetany by altering the albumin binding of calcium such that the ionized (physiologically influencing) fraction of calcium is reduced; one common reason for low carbon dioxide levels is hyperventilation."