so he breathes throught his mouth and gets more air
That doesn't make sense. Breathing in through your nose allows more oxygen to your bloodstream, if I remember correctly. I'm a runner, and my coach always told me to breathe in through the nose, out the mouth.
Its not that breathing through your nose gets you more air... Breathing through you nose filters all the crap out of the air (with your nose hairs )... so the air you breathe through your nose is essentially cleaner...
edit... some one already beat me to it
yeah but you dont get enough air.
enjoy passing out on your dh run if you breathe through your nose