Masking might even help asthma suffers.
http://biophysics.jhu.edu/classes/250.106-300-306/documents/EXAMPLE3.PDF The possibiltiy of getting bloodshot eyes
quote:
While also promoting angiogenesis, hypoxic hypoxia
can also cause petechial hemorrhages in the retina and throughout the body.
might mean you're overdoing it. But this article indicates there are some physical benefits. Also another source for asthmatics is for breathing less. You don't want too much oxygen either.
Brain damage will occur when there is still a lack of oxygen 4 minutes after loss of consiousness.
Alex
