Breathe through your nose and not your mouth

I always wondered why coaches would always tell you to breathe in through your noise and out your mouth when running. Would it really make that much of a difference? I just thought it was the obvious reaons, to avoid getting a sore throat and to calm down your breathing. Although these are good reasons, it turns out there are many more that I had never considered or even knew existed. The link below pretty much says it all but some of the more interesting/less obvious reasons include...it increases your oxygen absorption, maintains regulatory breathing, the nostrils filter and warm the air (the mouth bypasses this), breathing through the mouth stimulates the goblet cells to produce mucous, slow the breathing and cause constriction of blood vessels. Also, the sinuses produce nitric oxide which is a pollutant but harmful to bacteria in small doses. Mouth breathing also accelerates water loss increasing possible dehydration. If you breathe through your mouth during the day you are more likely to breathe through your mouth when you sleep, causing you to snore, a precurser for sleep apnea. Sleep apnea can cause lots of medical problems and is a known precursor to heart attacks and dying in one's sleep. So remember to breathe through your nose and NOT your mouth!!

http://www.breathing.com/articles/nose-breathing.htm