[cdavis]

Exhales train low 02 tolerance, but don't do as much for co2 tolerance. With little extra 02 in the lungs and less than full blood shift, you're blood 02 level drops very fast doing exhales. You can see it clearly on an 02 meter. Given the right opportunity, you can make the nurse completely crazy with the reading on those meters; she'll think you're dead. Naiad's right, a BO on exhale is very possible. Don't fall out of your chair. I think the contraction thing is individual, I definitely get them, much more uncomfortable on exhale.

Connor