mt, that reference is to a yoga site.

In yoga, you are not breathing air, you are ingesting prana, the fundamental life force (according to Hinduism anyway). If this was meant to be a religious discussion, please allow me to withdraw my previous comments.

Mouth-air and nose-air get mixed near the back of the mouth. I'd be grateful for any theories on how this would affect the efficiency or quality of air going to the lungs.

The pressure drop breathing in through the nose is negligible, and the energy in opening and closing your mouth every breath is unlikely to be significant either. Both of these would favor mouth-breathing anyway.

Thanks MT

The site I referenced as you did also, is for the Lance Armstrong Live Strong Foundation.
He's famous for being a biker, but like all world class athletes, he cross trains. I know he runs/lifts weights, and wouldn't be surprised if he did some Yoga or Pilate's as well.

The picture was meant to convey nose breathing during strenuous activity. I'm guessing certain yoga poses would be considered strenuous at least for me they would be

I can see how you might think it was a Yoga site, but if you read all of the info, it's clear that it's not. MT"s link leaves little doubt that the experts they refernece believe you should breath in thru nose, out thru mouth.
 
They mentioned some yoga poses that dictate you breath thru your mouth, but that's for specific working of core muscles, a technique like I believe your mouth breathing when climbing is. They also reference the fact that mouth breathing stimulates the flight or flight response. Tenses the body for the conflict to come. That tenseness may be useful for working deep core muscles and probably some martial arts techniques.

I'm a big fan of boxing/mixed martial arts fights. Ever see a boxer using nasal decongestants before the fight to clear their nasal airways.
Ever hear the fight announcers/analysts, comment that he's " sucking air", breathing heavily thru the mouth? That's a sure sign that their out of gas and ripe for the taking. Same with Basketball players on the court during foul shots. If they have their hands on their knees and breathing deeply thru mouth, it's sure sign their gassed.

If anyone doesn't think it matters whether you breath thru nose or mouth, here's a little " unscientific" test you can try
Do your normal workout breathing the way you normally would. If you've learned better, your breathing in thru nose, out thru mouth. If not your using a combo of both and as you get fatigued, your probably mouth breathing exclusively.
The next time you do the same workout, get some of those nose clips the swimmers wear, and do your entire workout just breathing thru your mouth exclusively.
If your honest I believe the majority of people would say it's much harder without some nasal breathing, and maybe even impossible with just mouth breathing.

Like MT, I don't claim medical expertise on this subject, but I do have plenty of experience with the subject.

From 35 to 50, I did 5-7 Aerobic/Spinning/Step/ Double-Quad step classes a week. 1 hour, 5 minute warm-up- 45 workout-10 minute cool down and stretch.
When I first started I was a 50-50 person. Started breathing thru nose, as I fatigued I started gasping for air thru my mouth. In the beginning I blamed it on simply being out of shape, but as I progressed and made friends with the different trainers and instructors over the years, they took me under their wings and got me eating right and learning how to breath properly. That put me over the hump so to speak. I could finish a class as strong as I started, something the " mouth" breathers never could

I have mentioned this before but it bears repeating (at least I think it does ). When I started p-90x it kicked my butt (and still does actually) and when I got to the Yoga routine included in the program I thought..."Oh great, a break" Man was I in for a surprise. I did 1/2 of a 90 minute routine before I was toast.

ST, I want to emphasize the breathing suggestion I am advocating is to breathe through the nose but forcefully exhale through the mouth. Repeat until you feel settled. Often it might just be 3 or 4 loud exhalations before I feel settled (still proceeding with the activity BTW).  repeat as needed.

Quote:


I don't argue with that at all. You mentioned feeling " settled". I think what your doing is as much a " relaxation/centering" technique as anything else. Same when climbing a steep stretch. Your focusing on filling your lungs completely, exhaling and emptying them.

That's a far cry from breathing/exhaling just thru the mouth all the time.
MuleLars found out what I was talking about when he made the conscious effort to breath in thru his nose, exhale thru mouth. He found it most useful as he cranked up the workload, not surprising as from the links you and I posted, that's how you receive the maximum oxygen intake with the least stress on you body. The goal is to be able to do it without thinking, just returning the body to the state we all started in, as NOSE breathers. IF he can learn do re-set his breathing all the time, he'll feel the difference and the benefits no matter what activity he's pursuing. Even one's that his significant other might enjoy
Women like men with ENDURANCE

Interesting conversation.  This thing about breathing in through the nose is actually very subtle.  The main reason to breathe through the nose as opposed to the mouth, is for greater breathe control.  Whether you breathe out through your mouth or your nose varies between traditions and practices (most martial arts breathe out through the mouth but many yogic practices (Ayengar being an example) breathe in and out through the nose.  At any rate when we talk about breathing through the nose we’re not talking about simply breathing through the nostrils.  What do I mean?  Stand in front of a mirror and breathe through your nose deeply.  Unless you have practiced this you will probably notice that your nostrils flair just slightly with each in-breath.  That’s nostril breathing which isn’t quite what we’re after.  Now try breathing in through your nose again but this time as though you were just slightly snoring (there should be absolutely no flairing of your nostrils.).  So the focus is at the back of your nose.  You should be able to hear yourself as though you were quietly snoring.  Notice how much more control you now have in the amount of air you can draw, how effectively it reaches your lungs (which feels like your belly – i.e., it expands with each inspiration) and the control you have as to the speed with which you draw it in.

Credentials (for MT’s benefit):
25 years practicing Chito Ryu Karate (until my hips gave out)
40 years as a meditator
PhD in Consciousness Studies (which includes investigating the nature of deep meditative experience.)