How am I supposed to breath with no air?

No, seriously, please tell me how. I laughed when my bro told me running at this alititude might make things a tad more difficult. "I'm a seasoned performer", I thought. "It's a 45 minute run!". 42 minutes actually and the first half was the hardest I've ever done. In 2.7 miles I gained about 1000ft in height and it was bloody tough going.

OK, apperently you need to hit about 8000ft for the oxygen content to be significantly less (thank you Wiki) so the post title isn't totally scientifically accurate, but apperently barometric pressure is reduced thus making it harder to train (Wiki again). 7:06min/miles would normally be an abomination, but in the circumstances I think I'll take it...

P.S. Apologies for the typos, the spell check is in French... bof!