Mike wrote:

> Is there any evidence that breathing harder
> > introduces more gas into the body, which in turn raises the levels of
> > saturation?

> My response would be I don't know. My guess would be not, the
> ambient pressure is not changing just because you are breathing
> harder.

My guess would be the opposite, because breathing more often results in a
net increase in the average partial pressure of the gas your body absorbes
in the gas in the lungs because the gas your body absorbs is replenished
more often.  Even if I'm right, I doubt the difference would be enough to
matter over the reasonable term.

Lee