Breathing. Mouth or nose

both-you have to keep the nose in play to blow snot rockets.

I sleep, run, bike, swim and daily life breathing with my mouth.

Mostly mouth.  Think about it this way - if you are trying to move the air in and out, you want a bigger hole.  Imagine breathing through a straw versus a big wide open mouth.

I breathe in and out with BOTH while running. You need as much oxygen in your body as you can get.

hmm...i breathe thru my nose only. I feel this keeps my breathing relaxed and in control. it also keeps my mouth/ throat moist.

Both mouth and nose. I can't get enough air by just breathing through my nose only.

Both!

depends on how bad my allergies are. If it is bad out then I am breathing only through my mouth because I have no choice. If it is good out I usually breath through both depending on how hard I am pushing. Usually it comes down to what is most relaxed and feels the best for me.

Get air into your lungs through every hole that you can...

Mike

I just breathe.  Never think about it until I try to run with a stuffed up nose and can't get enough air.

So I guess I do both.

how can you breathe through your mouth but not your nose (without pinching your nostrils)? I just tried it and couldn't do it

I breathe through any orafice connected directly to my lungs during all events all the time.

They say breathing through your nose allows you to control your breathing better and be more rhythmic. However, I agree with the masses. Whatever gets the most air into the lungs is best when you are gasping for air. IF you are on an easier more controlled run, try the nose, it seems to lower your heart rate. 

I breathe in through my nose and out through my mouth...

it helps me stay relaxed, and if I'm focussing on my breathing, then I'm not tensing up the rest of my body, allowing me to run easier/faster.

*my experience*