Should I be exclusively breathing through my mouth when I run? I seem to have chronic nasal congestion where one of my nostrals is always at least partially clogged.

I find that i cant breathe out of my nose when running as i merely cant get the amount of oxygen that my body seems to be demanding - where as breathing throught mouth, whilst its still down from what it needs, it is at least better.

I think I breathe through both nose and mouth. But I have a slightly different (and very irritating) problem: On at least one of my runs each week, my ears start to feel blocked, especially my left ear. I'm left shaking my head like a dog (which must look weird to passers-by), but effectively my ears don't feel very pleasant, and I can't seem to shake it. And no, swallowing doesn't help either. Any ideas?

I've been told by many "fitness instructors" over the years to breath in through the nose and out through the mouth.

However, I fnd that when in the middle of a particularly gruelling run, whatever gets enough O2 into the lungs is best.

I agree with you sr1312, as long as you are breathing it doesn't matter how.

There are some advantages to breathing through the nose, ie air gets warmed and filtered before hitting the lungs. However the relatively small area of the nostril openings compared to that of your mouth seriously limits your oxygen needs when you are exercising at a more brisk pace!

Breathe through your mouth, it's more esthetically (sp!?) pleasing also!