Better for your lungs, but I do not see how it is better for your heart.

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Reverend Dr. Jay
Lake of the Pines Triathlon fastest bike course record holder - Golden State Super Sprint fastest tri course record holder - Wildflower Long Course slowest run course record holder (4:46:32)

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"If you have a body, you are an athlete." -Bill Bowerman

I've been to one spinning class in my life. That instructor told me that I didn't know how to ride a bike. The comment was something like "you and all your triathlon buddies don't know how ride." That same instructor showed up at a group ride. I showed the guy how to find his max heart rate repeatedly. I also showed him what it was like to get dropped.

I'm not normally that nasty, but, I don't do well with arrogance.

What was he instructing her in? I can see this might be an approved method for some things :)

I hope you made sure he remembered you from class. What a total jackass.

That's good advice for your lungs because the nose hairs partially filter pollutants from the air. I'm not sure it is possible when one is hammering. :)

Indoor and outdoor air pollution can wreak havoc on your lungs, particularly if you have asthma, chronic bronchitis, or emphysema.

-Robert

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"How wonderful it is that nobody need wait a single moment before starting to improve the world." ~Anne Frank

Isn't that yoga breathing? My girlfriend goes to spin classes also. I would rather be outdoors and I tell her she needs to get out and ride and not hang out with the "gym people". A few weeks she said she went on a ride with her spin instructor and the instructor didn't know how to change those "gear thingies".

Oh, I am not liking this at all.

Spin "Instructors" go to a one-day seminar taught by Schwinn. It's all about how to create a Reebok step class using a v-bike, and it's basically BS.

I led spin sessions for triathletes, and now I lead a spin group thrice weekly at my club. I get all the cyclists, and the step ladies go to someone elses "class." You can't get enough O2 through those tiny holes in your nose to stay with my spin sessions.

Breathing through your nose is a good way to keep yourself in zone 2 on long rides during base building season. If you need to open your mouth to get enough air, then you're hammering too hard. Spin is about anaerobic hammering 1,2,3,5 minutes at VO2 max. No way nose-breathing works for that.

Glad you taught that boy some humility. Spin can be a great strength and speed booster, but not the way most teach it.

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Cousin Elwood - Team Over-the-hill Racing
Brought to you by the good folks at Metamucil and Geritol...

[reply]...her spinning instructor told her that she should breath in through her nose and out through her mouth. ... he insisted that breathing in through your nose is better for your heart. [/reply]

Perhaps by "better for her heart" he meant that it could help her to keep her heart rate down? I know that slow, deep breathing can help keep the lid on if you're climbing out of the zone too fast, or if you're going to blow...

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<If you're gonna be dumb, you gotta be tough>
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Proud member of the Smartasscrew, MONSTER CLUB
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Breathing through your nose isn't better for the health of your heart, HOWEVER, it can actually increase cardiac output by decreasing intra-thoracic pressure (compared to breathing through a wide-open airway...your mouth), which facilitates venous return to the heart from the lower body. Really.

The heart acts as a sort of sump-pump in most normal situations...pumping out whatever is returned to it....if you return blood to your right atrium more rapidly by the "sucking action" of a more negative intra-thoracic pressure, your stroke volume will increase for a couple of beats. Exhalation should be done as non-obstructed as possible, for similar venous return reasons.

If you don't believe it, try this. Exercise at a steady state that requires breathing at a rate and effort that makes it hard to carry on a conversation. Note your HR. Now, suck air in through your nose instead of through your mouth. You'll see your HR drops a little...maybe 3-4 beats per minute. Your cardiac output hasn't dropped, but your stroke volume has increased.

As long as you aren't exercising so hard that you cannot get enough air exchange by inhaling through your nose, your heart will beat slightly less per minute by doing so compared to being a wide-open mouth-breather. Really.

But, it isn't "better" for your heart from a health standpoint.

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Quid quid latine dictum sit altum videtur
(That which is said in Latin sounds profound)

thanks for taking the time to write this, one learns something new every day (esp. here on ST, man, this forum is great!)

For those of us with allergies, sometimes those tiny holes don't do much at all.

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_________________
Dick

Take everything I say with a grain of salt. I know nothing.

Why do I have a sneaking suspicion that the spin instructor was not thinking about venous return when dispensing his advice... ;)

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_______________________________________________

jhc wrote: Why do I have a sneaking suspicion that the spin instructor was not thinking about venous return when dispensing his advice...

100% totally agree! They are paid to spin, not be physiology professors!

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Quid quid latine dictum sit altum videtur
(That which is said in Latin sounds profound)

This has been a very informative thread. Thanks for all the replies. I think I'll tell my wife her instructor is "full of it". She needs to spend more time outdoors anyway.

Thanks,
Victor

Sadly, people with allergies have a tougher time working out. You also have to find your zone 2 for LSD rides and runs by a more precise means than "can I breathe through my nose?"

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Cousin Elwood - Team Over-the-hill Racing
Brought to you by the good folks at Metamucil and Geritol...

that may explain why I have so much trouble staying there.

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_________________
Dick

Take everything I say with a grain of salt. I know nothing.

I've read and we all know that our ability to exchange oxy is limited by our bodies ability to do this exchange, not by how much you breath. The sensation to breath like a madman is more of a brain function to lessen CO2 in the body than what your actually using. Though it might not "feel" like it, your nose may supply the air you need. Perhaps this is what he's getting at and theory at some point may run out of air. Try it sometime, when you feel like opening the mouth, keep er closed and try long deep breaths and see what your heart and body is actually doing. Balls out top of the hill thigh screaming--mouth wide open.

You're kidding... Right???

My opinion.

With the serious, Kool-Aid drinking Spinning folks you'll see a lot of Johnny G's influence on the program... Heavy emphasis on eastern philosophies (yoga, martial arts, mind/body emphasis kind of stuff). Some seem to treat riding an indoor bike as almost a religious experience.

An example of a disciple...

http://www.plhb.com/index.html

From all the years of studying physiology, this seems far fetched to me. I could nuke you with scientific literature, but since you guys are all so hands on, I tried the experiment you suggested:

Suffice to say I came up with the opposite effect. Maybe there is something wrong with me?

I have to agree that sometimes deep breathing through my nose has a calming and relaxing effect and lowers my heart rate. But only when I sit in my office-chair and have to calm down.

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adrialin

(BOMK, racing drug and supplement free since 1985)

No, I'm not kidding. You don't recognize the effects of intra-thoracic pressures on rate of venous return and therefore stroke volume?

Inhaling (with sufficient force) through your nose (rather than your mouth) is achieved by increasing the negative intra-thoracic pressure, which facilitates extra-thoracic venous return. Increasing venous return increases stroke volume in a mild-moderately exercising upright person.

One of the reasons CPR works is the change in thoracic cavity pressures in relation to extra-thoracic pressures. The valves in the heart keep the blood moving "forward", but, it isn't just the pressing and removing pressure on the heart that causes circulation during CPR.

If you still don't believe it, try it. It's not hard to demonstrate.

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Quid quid latine dictum sit altum videtur
(That which is said in Latin sounds profound)

Let's hope.


Read the reply to JustCurious. You two amaze me.

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Quid quid latine dictum sit altum videtur
(That which is said in Latin sounds profound)

Sweet! There was a spin instructor at my old health club in Chicago that was a jackass, wish I had a chance to do the same.

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-----------------------:)
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adrialin wrote: From all the years of studying physiology, this seems far fetched to me. I could nuke you with scientific literature...

OK, go ahead. I'll bet you cannot show me one piece of scientific literature that will state than increasing negative intra-thoracic pressure doesn't increase venous return (provided there is venous return available in the extra-thoracic spaces with no obstructions to flow). In a steady-state mild-moderately exercising person, increasing venous return will be reflected by a slightly decreased HR.

When you inhale, you do so by decreasing intra-thoracic pressure. If you inhale in a manner and at a rate that is high enough to require even lower intra-thoracic pressures than usual (such as through your nose when exercising mild-moderately, probably even moderately-moderately hard), this lower intra-thoracic pressure actually facilitates blood return to the heart from extra-thoracic sites.

Since the heart is operating at only a mild-moderate, or moderate-intensity, it's stroke volume likely isn't at it's maximum, and since the heart acts as a kind of sump-pump (pumping out whatever volume is returned to it), this increased venous return will result in slightly higher stroke volume for a few beats. Look up Starling's Law if you don't believe it.

The heart responds to several feedback mechanisms which are in place to help maintain an appropriate cardiac output for the person's current metabolic needs. The body, in it's attempt to conserve energy, signals the heart to slow down just a bit, because the body's sensors detect more blood flow than is needed at the moment due to the several beats of increased stroke volume. If you facilitate venous return (and there are several ways to do this, sucking in harder through your nose compared to less-restricted inhaling through your mouth, submerging your legs in water, using compression pants on the legs, lying down, raising your legs above your heart, giving IV fluids, removing tamponade, correcting a hemo/pneumothorax, etc.), the heartrate will respond by slowing. It's basic knowledge used every day in medicine, and demonstrable in most anyone very easily on a stationary bike, or even a treadmill.

I stand by the statement: inhaling through the nose (during mild to moderate effort) will usually result in a slight decrease in heartrate due to increased venous return, when compared to inhaling through a less restrictive open mouth. I'm not talking about 10 bpm...just 2-3-4 bpm less.

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Quid quid latine dictum sit altum videtur
(That which is said in Latin sounds profound)

Big O wrote: Like JustCurious, this morning I tried what you suggested, and my heart rate appeared to increase, not decrease. This could have been due to the fact that even at a moderate exercise intensity, I found it difficult to maintain adequate ventilation when breathing only through my nose.

Of course...if you aren't moving sufficient volumes of air, your HR response will be to INCREASE, just as you noted. It's those wonderful feedback mechanisms at work telling the heart to speed up so more blood will go through the system and deliver the required oxygen.

Of note, this statement only works in mild-moderate exercise, and only if you breathe IN in a restrictive manner (nose) and OUT through a less-restrictive manner (mouth).

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Quid quid latine dictum sit altum videtur
(That which is said in Latin sounds profound)

Big O wrote: Inhalation requires established a negative intrathoracic pressure regardless of whether you breathe through your nose or your mouth. The latter would result in a markedly lower intrathoracic pressure during exercise if, and only if, you severely restricted the inflow of air.

I agree, inhaling through your mouth is less restrictive....inhaling through your nose would require a more negative intrathoracic pressure....right. Nobody said otherwise, did they? BTW, inhalation doesn't always require negative intra-thoracic pressure...ever heard of Positive Pressure Ventilation?...OK, that's just a joke, we're not talking about patients on ventilators here...we're talking about upright human athletes in a steady-state mild-moderate exercise with no other abnormal circumstances.

Then, Big O wrote: ...since pulmonary arterial pressure is quite high relative to intrathoracic pressure during exercise, small changes in the latter will have minimal effect on the transmural pressure.

Well, the purpose of the pulmonic valve (and to a much lessor extent, the tricuspid valve) is to keep that higher pressure pulmonary blood on the the pulmonary side. The CVP isn't so high during exercise that forcibly increasing negative intrathoracic pressure (by sucking in through your nose, for a specific example) has no effect on venous return.

I already answered your point 3...this decreased HR response goes out the window if ventilation is compromised...that's why I kept saying mild-moderate steady-state exercise.

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Quid quid latine dictum sit altum videtur
(That which is said in Latin sounds profound)

It wasn't me who gave it a try. I have better things to do. I'm still trying to master that 'rub your tummy, pat your head at the same time' thing.

OK. I'll play.

Does rapid inhalation through a restriction (the nose) lower the partial pressure of O2 in the lungs, thus inhibiting oxygen uptake?

JC's attempt to play: Does rapid inhalation through a restriction (the nose) lower the partial pressure of O2 in the lungs, thus inhibiting oxygen uptake?

Obviously, a trick question.

Gas pressures in the alveoli aren't arithmetically directly linked to pressures in the trachea and bronchi unless enough time is allowed for equilibration (and, at artificial ventilation speeds of 8-10 per minute, this could occur, but, not as likely in our subset). While there may be a slight decrease in gas pressure at the alveolar level, I'll say O2 diffusion is economical enough not to result in a clinically decreased transfer of O2 through the alveolar membrane (the answer could be determined by sampling the pulmonary venous PO2) in the subset of the mild-moderately exercising athlete.

OTOH, yes, PEEP will help to raise PO2, if that's what you're getting at, so, wouldn't negative pressures drop O2? I'm sure you realize that PEEP will sometimes decrease cardiac output...if you already know this, surely it isn't a quantum leap to understand increasing negative intrathoracic pressures can increase cardiac output due to higher stroke volume, right? And, if you increase cardiac output in a steady-state mild-moderately exercising athlete, the body's response will be to slow the HR a couple-few beats per minute....just like I've been saying.

Thanks for playing!

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Quid quid latine dictum sit altum videtur
(That which is said in Latin sounds profound)

We're talking miniscule, practically insignificant things here.

How do you conclude which tiny, essentially unmeasureable factor is significant and which one is not?

If I cover one nostril thus decreasing intrathoracic pressure even more, will my heartrate drop even more?

Does the same hold true near maximal intensities? Can I increase maximum cariac output by nose breathing?

I think maybe a reality check is in order here. Your "and then a miracle occurs" step seems to be that nose breathing actually does cause a detectable decrease in intrathoracic pressure. You state "Gas pressures in the alveoli aren't arithmetically directly linked to pressures in the trachea and bronchi unless enough time is allowed for equilibration (and, at artificial ventilation speeds of 8-10 per minute, this could occur, but, not as likely in our subset)." So nose breathing DOES affect intrathoracic pressure but doesn't affect Po2?

Big O wrote: But until the pulmonic valve opens, no filling occurs. The transmural gradient that matters is therefore the one present during diastole, not systole.


Do you mean filling of the pulmonary vasculature here? That doesn't make good sense, you don't fill the pulmonary vascular sytem, you inject some blood (RV Stroke volume into it), but, you don't "fill it". Filling of the right ventricle occurs through the open tricuspid valve with assistance or "kick" from the right atrium while the pulmonic valve is closed. It doesn't matter what the pressure is in the pulmonary artery as long as it isn't so high that the right ventricle doesn't normally empty...and if the RV doesn't normally empty, the Starling's Law of the Heart effect results in a slightly higher stroke volume on the subsequent beat (assuming normal PVR and RV force of contraction). And, if the RV was normally emptied, increasing venous return (therefore increasing the volume in the RV during it's subsequent beat), you would have a higher stroke volume.

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Quid quid latine dictum sit altum videtur
(That which is said in Latin sounds profound)

JC wrote: If I cover one nostril thus decreasing intrathoracic pressure even more, will my heartrate drop even more?

Does the same hold true near maximal intensities? Can I increase maximum cariac output by nose breathing?


Obviously, you're not paying attention to the mild-moderate exercise intensity part of the athlete. The answers are no, no, and no to those three questions.

The answer to your last question is as follows, and I'll try to state it more succintly: breathing sufficiently quickly through a restrictive device (such as your nose) does decrease intrathoracic pressure, which increases venous return...often enough to result in a couple-few bpm decrease in HR in a mild-moderately exercising athlete at steady state. I don't think that in a mild-moderately exercising athlete, that this decreased intrathoracic pressure causes enough of a decrease in oxygen transferred across the alveoli to clinically negatively impact the PO2...(THIS PART IS NEW) if this were to be the case, the initial slight decrease in HR would be met by an increase in HR due to the body's feedback mechanism signalling inadequate oxygen delivery.

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Quid quid latine dictum sit altum videtur
(That which is said in Latin sounds profound)

The Big O wrote: This is not a given. For example, exercise in the supine position increases cardiac output by about 10%, but actually results in an increase in heart rate.


I agree with you on this. It's because the venous return is enhanced enough in a supine exercising person that stretch receptors in the RV wall tell the heart to hurry-the-hell-up and beat faster so we can get this backlog of blood out of the right atrium.

Why you try and change the initial set of circumstances is beyond me...

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Quid quid latine dictum sit altum videtur
(That which is said in Latin sounds profound)

I wrote: and demonstrable in most anyone very easily on a stationary bike, or even a treadmill.

The Big O's response was:

I could not demonstrate it.

My response: Well, you changed the initial circumstances...as you reported, you were exercising at a rate such that you couldn't exchange gas fast enough to provide the required exchange in your lungs by breathing through your nose. Try and keep the initial set of circumstances, or certainly, the HR would go up in this case...just as yours did.

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Quid quid latine dictum sit altum videtur
(That which is said in Latin sounds profound)

The Big O wrote: Furthermore, while such hypoxemia is most evident during very high intensity exercise, some individuals experience a drop in arterial saturation even at modest intensities.


BOTH of your cited studies worked with high-intensity training. The fact that some individuals experience a drop in arterial saturation at modest intensities (what was their HR at this modest intensity as related to their Maximum HR?) is inconclusive as to whether THESE individuals would have a slight decrease in HR at a mild-moderate level of exercise by breathing in through their nose at a sufficient negative pressure to increase venous return.

Again, quit trying to change the initial circumstances. It's not germaine. You to change the intial circumstances to fit your arguement...your aguement fits your circumstances, but, your circumstances aren't fitting the ones I put forth.

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Quid quid latine dictum sit altum videtur
(That which is said in Latin sounds profound)

I wrote: The CVP isn't so high during exercise that forcibly increasing negative intrathoracic pressure (by sucking in through your nose, for a specific example) has no effect on venous return.

Big O wrote: Prove it.

Prove otherwise. We could both create scenarios where each would be correct. You'd change the circumstance, such as having someone on a decline position, or in water, or exercising at a very high effort level, etc. Or, you'd have someone inhale less forcibly than I would have, and we'd still have a standoff.

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Quid quid latine dictum sit altum videtur
(That which is said in Latin sounds profound)

Big O wrote: Since you cannot prove the negative, let's see you point to one piece of scientific literature showing that it does.

From "Clinical Applications of Respiratory Care" by Shapiro, Harrison, and Trout. Page 48 and 49: "...venous blood flow to the heart from gravity-dependent areas of the body is regulated by three factors: (1) tissue pressures, (2) the venous valvular system, and (3) body cavity pressures....Upon entering the pelvic and abdominal region, venous blood flow depends primarily upon intra-abdominal pressures exceeding intra-thoracic pressures....these factors of....intra-abdominal-to-intra-thoracic pressures are extremely significant..."

Furthermore, since about "...65-70% of the blood volume is contained within the venous system....the venous systems are extremely important in effective circulation."

It's obvious that the gradient increase of a more negative intra-thoracic pressure results in an increase of venous blood return from the gravity-dependent areas of the body, because a more negative intra-thoracic pressure effectively increases the intra-abdominal-to-intra-thoracic pressure gradient.

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Quid quid latine dictum sit altum videtur
(That which is said in Latin sounds profound)

Hey, Big O, I did a little informal experiment this am with three others on bike trainers. I hope you find it interesting, and maybe you'll agree the idea may not be so off-the-wall as you originally thought. It's no thesis, and not meant to be, just read it all if you would, please.

After warming up 15 minutes, each rider settled into an easy pace...whatever gear and rpm each person found to feel easy, and kept the gearing and cadence constant until for 5 minutes, noting the HR to make sure it was stable. My HR was ~126, Sam's was ~135 (he's younger!), Bill's was ~130, and John's was ~128. We all used the same Polar HR monitor, BTW. At this time, the rider began to breathe in deeply through the nose and out through the mouth, and we noted what happened to the HR.

Every one of us had an initial tick up in HR of 2-3 bpm from baseline that lasted a few 5-10 seconds, followed by a decrease in HR of 3-5 bpm from baseline that lasted 30 to 45 seconds. Then, the HR returned to the original baseline, even though we continued to breathe in through the nose and out the mouth.

Here's the more interesting part: when we stopped breathing in through the nose, everyone's HR went UP above the baseline rate...and stayed up for 20-35 seconds, before returning to baseline.

I theorize this HR pattern is an example of cardiovascular equilibrium changes between the arterial and venous systems, due to manipulation of venous return from the gravity-dependent extra-thoracic venous blood, brought about by forcibly changing intra-thoracic pressures by breathing in through the more restrictive nose.

Here's why: The initial uptick in HR is probably due to the normal increase in HR associated with inspiration (due to decreased vagal tone, often referred to as respiratory variation of HR, and it's usually more pronounced in younger people) combined with a normal response of the heart to increased venous return; the normal right heart will increase rate via the S-A node, as a result of signals from atrial stretch receptors (via the cardioaccelerator center...a part of the sympathetic system) when given more volume.

This increased blood flow from the right atrium, and then RV, pushes through the lungs to the left heart in just a beat or two, and then the Left Heart has a beat or two of increased volume (obviously, the left heart has the same rate as the right heart). The baro-receptors in the carotid bodies and aortic arch sense a greater pressure, and the normal vagally mediated feedback mechanisms tell the heart to slow down. Also, since LV cardiac output is momentarily higher due to the increase stroke volume, and higher LV cardiac output is not needed by the body, other feedback mechanisms (than the baro-receptors) may also signal the heart to slow slightly. For whatever reasons, we see a decrease in HR of a few bpm. However, after 30-45 seconds, a new equilibrium is reached between arterial flow and venous return, (we can't augment venous flow from the extra-thoracic venous blood indefinitely by simply increasing negative intra-thoracic pressure) and the HR returns to baseline.

Then, when stopping the restrictive nose inhalation and returning to "normal", less restrictive inhalation, there is a momentary decrease in venous return rate to the RA, therefore RV stroke volume decreases, LV preload and stroke volume decreases, aortic and carotid bodies sense a decrease in pressure and signal to increase the HR, and the HR increases above the original baseline in order to attempt to maintain required cardiac output and/or satisfy the aortic and carotid body pressure receptors.

A new equilibrium is being established where the venous blood return matches arterial outflow, and the HR again decreases to the original baseline.

We tried it at slightly higher effort levels, too. Circa 145 bpm. Got the same results: Start nose inhalation, see an initial uptick of HR lasting 5-10 seconds, then a decrease in HR from baseline lasting 30-45 seconds, then return to baseline. Stop nose inhalation, see a rise in HR that peaks above baseline for 20-35 seconds, then settles back to baseline HR.

Last comments: I knew the HR would drop using this set of circumstances, I didn't know the drop was so short lived. The way the results look to me is that there probably is a significant change of venous return by breathing in the manner we did, but, the body is able to establish, and re-establish, equilibrium in a relatively short period of time. Thanks for giving me a reason to look into this further...it's interesting stuff to me...even if you don't agree to all the particulars. Like I said, it's not a thesis, just some observations and theory as to what is going on.

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Quid quid latine dictum sit altum videtur
(That which is said in Latin sounds profound)

Oracle,



I was SHOCKED that you experimented something with yourself and presented the "results". I cannot believe you broadcasted such anedoctal, experience-of-one information. Shame on you! ;-)



Anyway, sounds like as usual you're right and yaqui is wrong. But I can see a business opp for yaqui here. He can design a sort of powercrancks for the nose. I can picture it, a gizmo that will alternatively close one nostril or the other. That way increasing cardiac output even further! I can see its name, "POWERNOSE"... catchy...

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-
"Yeah, no one likes a smartass, but we all like stars" - Thom Yorke


smartasscoach.tri-oeiras.com

I did do my part of the experiment while on my PowerCranks!

Too bad it looks like the benefits of the "in through the nose" technique is so short-lived. At least, since (according to Big O) my PowerCranking is useless, it's a long-lived uselessness!

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Quid quid latine dictum sit altum videtur
(That which is said in Latin sounds profound)

Oracle? JustCurious? Are you two through playing?

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Quid quid latine dictum sit altum videtur
(That which is said in Latin sounds profound)

It makes sense to me, in a theoretical kind of way. It's kind of like breathing through a straw. you make a giant sucking motion, and your chest tries to expand... but air doesn't get there fast enough, so something has to take up the additional space. it's completely possible that it's gonna be the only other thing that really moves around the body: blood.

I can't prove it, but it sounds theoretically valid.

>> In the nose and out the mouth?

I am glad he did not suggest to her that she should have it "in the mouth and out of the nose..." could have been a complete mess.

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but air doesn't get there fast enough, so something has to take up the additional space.

Theoretically, wouldn't the air that did get there simply expand to fill the available space?

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"People think it must be fun to be a super genius, but they don't realize how hard it is to put up with all the idiots in the world."

AHub wrote: but air doesn't get there fast enough, so something has to take up the additional space...blood.

Vitus is correct, the air already there expands...it isn't a perfect vaccuum. However, not only is this idea of increasing extra-thoracic venous blood flow rate theoretically valid, it's clinically demonstrable with a pulmonary artery catheter, echocardiogram, and a HR monitor. Don't let those that apparently have little to no experience with the subject of right heart function/venous return as it relates to left ventricular function/BP/HR try and tell you otherwise. Having someone bring up anything about the pulmonic valve, and then refusing to clarify what was intended, only shows a unfamiliarity with the subject.

Making the intra-thoracic pressure more negative will, indeed, increase venous return to the right heart (especially in combination with increased intra-abdominal positive pressure, thanks to the one-way valve system in the legs...as is observed when contracting the diaphragm), which has an almost immediate effect on Left ventricular output. Affecting LV output in this way will then affect HR.

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Quid quid latine dictum sit altum videtur
(That which is said in Latin sounds profound)

I wrote: I'll bet you cannot show me one piece of scientific literature that will state than increasing negative intra-thoracic pressure doesn't increase venous return

The Captain wrote: Since you cannot prove the negative, let's see you point to one piece of scientific literature showing that it does.



I gave you one piece of literature with no response...here's another:

"Aust J Physiother. 2003;49(4):253-8.
Effects of ankle exercise combined with deep breathing on blood flow velocity in the femoral vein.

Kwon OY, Jung DY, Kim Y, Cho SH, Yi CH.

Department of Physical Therapy, Yonsei University, South Korea. kwonoy@dragon.yonsei.ac.kr

Ankle exercises are commonly used to facilitate venous return in the lower extremity and to prevent deep vein thrombosis. Moreover, the respiratory cycle affects venous return. This study examined the effects of ankle exercise combined with deep breathing on the blood flow velocity in the femoral vein. Twenty healthy males (mean age 21.3 years), who had no medical history of lower extremity disease, were recruited for this study. The blood flow velocity in the femoral vein was measured while performing four exercise protocols: quiet breathing while resting (QR), deep breathing (DB), ankle exercise with quiet breathing (AQB), and ankle exercising combined with deep breathing (ADB). Using a Doppler ultrasound with an 8 MHz probe, peak blood flow velocities were collected for a 20 second period at the start of the inspiration phase in each protocol, three times. There were statistically significant differences in the peak blood flow velocity in the femoral vein with the four protocols (p lt 0.001). The mean (SD) peak blood flow velocity in the femoral vein was as follows: QR 10.1 (4.2) cm/sec, DB 15.5 (3.9) cm/sec, AQB 20.7 (6.6) cm/sec, and ADB 26.5 (9.4) cm/sec. Post hoc analyses revealed significant differences between each of the four protocols (p(adj) lt 0.01). The mean peak blood flow velocity in the femoral vein was greatest with the ADB protocol, which implies that the ADB protocol may be useful to prevent the blood stasis in patients at risk of deep vein thrombosis."




This paper demonstrates that not only does deep breathing increase extra-thoracic venous return in resting people, it does so in mild-moderately exercising people, the negative intra-thoracic pressure effect on venous return is significant enough to be demonstrable all the way down to at least the femoral vein. There is no reason to believe that dropping the intrathoracic pressure even further (by breathing in through a more restrictive opening, i.e., the nose) wouldn't result in even greater venous flow.

Mind you, as I already pointed out (but I suspect you didn't bother to read it), there will come a time of equilibration where the increased venous return effect will be diminished to probably the level of "normal breathing during exercise". My informal "study" with three other people shows that in a short period of time: 30-45 seconds, the HR returns to normal, I suspect due to this equilibration of left heart output, right heart output, and effective splanchnic volume.

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Quid quid latine dictum sit altum videtur
(That which is said in Latin sounds profound)

Ok... I have been reading all of the previous threads regarding your question of "breathing in through your nose and out your mouth" and have something for you to look into. I recently read a book titled "Body, Mind and Sport" by: John Douillard which covers this said topic matter. What his research has shown is this... while allowing your body to "relax" while training and NOT "stressing" your systems one can achieve athletic goals without pain and anguish as previously thought. I know, it seems counterintuitive however, I even have a B.S. and M.S. in Exercise Physiology and questioned the whole theory in a big way at onset. However, I was experiencing recurrent injury(s), lack of motivation to train "hard," a plateau of my triathlon performances and an overall lack of drive to train due to the Pain associated with it. Before anyone jumps on me for being a wuss I think I should point out that I race as a professional and do rather well albeit I am still developing. Anyway, while trying this method of breathing in through my nose AND OUT through my nose i have found my training to be more enjoyable, I feel "in the zone" more often, I am able to sustain efforts at MUCH lower HR's than previously observed and I can now even perform intervals while running and cycling at the same pace and now even faster paces than previously would have sent me over the edge panting, and essentially struggling to complete. I have found that almost every session I perform is completed BEFORE I am completely smoked, before I push myself to the brink and end the session wanting more... which in essence is what interval training should do. The basic model is based on the principles of Ayurvedia (Indian Medicine). Before all of the Allopaths jump all over this I suggest that you read the book and get back to me! I trust that some of you will try and most of you, if not all, will find the true enjoyment of training and racing for a lifetime instead of ending it due to injury or lack of motivation. Good Luck!

If you train better doing this, great. You don't have to have a PubMed article telling you it's effective in order for it to be effective for you. Sure, it's a bit Zen-like, who cares? Some of my best exercise experiences have been Zen-like!

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Quid quid latine dictum sit altum videtur
(That which is said in Latin sounds profound)

Is this thread not living proof of our ability in triathlon to comlicate the most simple of matters?

Isn't the latin phrase 'reductio ad absurdum', or some such?

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kiwipat

per ardua ad astra

kiwipat wrote: Is this thread not living proof of our ability in triathlon to comlicate the most simple of matters?


It sure seemed simple to me....a couple of people are certainly of a different opinion, or are shrinking violets after throwing a few darts my way...it's the "hit and hide" stuff that gets me to keep going on about it. No longer, though; you're right. Enough is enough.

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Quid quid latine dictum sit altum videtur
(That which is said in Latin sounds profound)

 I read the book and have always wondered why no one else has referenced it pro or con. I guess I'll throw my two pennies in on this since you were brave enough to do the same. No I won't "nuke" anyone with literature references this will be mostly anecdotal evidence with some begining anatomy.

I do agree with Cousin Ellwood that the nose provides for a good limiter on what the body can do in regards to activites that have an oxygen demand, which for most beginers and those looking to maintain health this is probably a good thing. I guess it is kinda like a restricter plate in NASCAR, that is it keeps HP down by limiting the available oxygen.

I started training using the Douillard method (nose breathing) and found it extremely hard to maintain initially. At first that was my focal point of concentration. If it wasn't I would revert back to mouth breathing. This was most notable for running, for biking it was fairly easy. I still have not perfected it in the swim. Some of this may be due to my being a biker first, runner second, and a struggling swimmer.

I now can run and bike within a few beats of max by nose breathing alone (not sure what this proves, but it feels good to me).I have no problem where my speed is so maybe there is a gain by opening my big fat bug catcher but for 99% of my riding I am not interested in accessing that pathway.

This is laymans interpretation of what is happening; Douillard asks that you sit relaxed and take a deep breath from the nose and then from the mouth. For me (this could be through suggestion) nose breathing caused deep diaphramatic breathing which supposedly accesses the lower lobes of the lungs which are better at oxygen exchange.Deep mouth breathing caused my shoulder girdle to be raised indicating the upper lobes where being used which to my knowledge are less efficient at O2/CO2 exchange than the lowers.

A discussion with my anatomy prof also brought out that he thought the raising of the shoulders could also cause the baroreceptors in the neck to see an increase in pressure thus triggering the heart to beat faster to overcome it. If I remember right at a certain point of HR the heart becomes very inefficient (atriums cannot deliver fast enough to the ventricles) so it seems logical that if you can avoid a hormonal cascade that will ultimetly cause INEFFICIENCY of blood flow then this should be avoided.

There is also something about "dwell" time in the lungs. Rapid mouth breathing causes insufficient time for efficient O2/CO2 exchange to occur while slow nasal breaths promotes this.

All I have to say is that it works for me. Yes it is kinda zen like but that doesn't bother me.

I to have witnessed the decrease in HR when I go back to nasal breathing after losing focus and reverting to mouth breathing. I must also say that it doesn't always work but I have attributed it to me going to far over the limit as you sometimes need/want to do (i.e. fast group ride, impending T-shower or just plain you want to ride fast). This is also a pace that I could not sustain over a long distance so that is really a moot problem for this forum. Mind you I am NOT a world beater but I can hold my own so maybe this does not hold up at an "elite" level.

I do not think that suggesting nasal breathing to a beginner is a bad idea even if it is from just a "spinning" instructor. Those comments remind me of my son who thinks he's the schizznitz because he can bench more than his mom...BFD

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It is good to hear that others also feel that we can throw a bunch of pubmed journal articles up to refute or support ANY topic we wish but what it comes down to is this... what works for you may not work for others! With all of the research and reading that I had to do for my undergraduate thesis as well as for my Masters Thesis it still amazes me to think that some believe that one way will work for everyone! I digress.

In reading your statement about your conversation with your professor and his thoughts on the subject I had thought of that correlation but I guess it never really sunk in. The baroreceptors in the Carotid body are very sensitive to pressure changes and I can imagine that with the elevation of the thoracic cage that they would in fact be affected if one was to breathe from their chest as apposed to from the diaphragm. good point.

with swimming, Douillard does make the comment that breathing through ones nose is pretty much impossible but the same diaphragm concentration should be considered while in the pool but while breathing through ones mouth.

One thing to consider is that the development of overall efficiency is done primarily "aerobically" albeit some time devoted to developing lactate clearance is beneficial obviously. with the nose breathing method one pretty much is forced into utlizing the more efficient aerobic metabolism and as a result, lipid metabilism. This would essentially act as the "restrictor plate" that you speak of. I am not saying that this method is the end all but from what i have experienced, from what the athletes that I coach have experienced and from others experiences this method deserves a deeper look.

Zen like... maybe. but i think that what many do fail to do is to really "read" what their bodies are telling them. we, as anal retentive athletes tend to do whatever is on our meticulously designed training plans or whatever we read on the latest XTri.com presentation INSTEAD of listening to our own bodies over time and sitting the set out when the time calls for it or pushing through when we actually can and should. Just my two cents!

What is "lactate clearence"?

And this whole sentence here "one pretty much is forced into utlizing the more efficient aerobic metabolism and as a result, lipid metabilism".

For higher intensities than the one obtained by restricting your breathing, you don't utilize the aerobic metabolism?

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"Yeah, no one likes a smartass, but we all like stars" - Thom Yorke


smartasscoach.tri-oeiras.com

"with swimming, Douillard does make the comment that breathing through ones nose is pretty much impossible but the same diaphragm concentration should be considered while in the pool but while breathing through ones mouth."

I guess I should have read that section better. After throwing up in the pool twice trying it I, with the help of the lifeguard on duty at the Y, came to the same conclusion.

Note to self; Start reading, stop skimming

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What is "lactate clearence"? Lactate Clearance is the affective clearance of the product of "anaerobic metabolism" known as lactate or Lactic Acid. Our cells essentially can introduce lactate through the membrane and use this lactate as a fuel source using the lactate shuttle (a debated shuttle at that!) when the workload decreases during the rest interval. In theory, when one consistently uses interval training they are in essence trying to produce some lactate and then during the rest interval or during the period of decreased workload the body clears it because at the decreased workload the body is more efficient at doing so. The ultimate goal... to increase one's lacate clearing ability or enhance one's lactate threshold.

And this whole sentence here "one pretty much is forced into utlizing the more efficient aerobic metabolism and as a result, lipid metabilism". By using the nose breathing method you are essentially forcing yourself to maintain an efficient workload, not more than you can handle in other words. lipid metabolism is more prevelant when one performs "aerobically" but lipid metabolism does not simply stop when we increase workload.

For higher intensities than the one obtained by restricting your breathing, you don't utilize the aerobic metabolism? I disagree. just because you are going "hard" does not simply shut aerobic metabolism off. It simply is reduced because the demand for ATP (what our cells use for energy) is greater than the supply via aerobic metabolism. We get a faster return of ATP from Anaerobic matabolism but with a cost... lactate. it is a big cycle.

thought you might be having that problem! Sorry man... I can only imagine what that must have been like... being the lifeguard not laughing at you must have been tough!

I did not clearly answer the last part of your question so i am back for more. Nose breathing is NOT restricted breathing at all. True, at first you will feel restricted and you will be slower. However, with time, your body becomes relaxed with this method and can hold paces that would normally cause stress and alot of fatigue. while breathing through your mouth, gasping for air and panting, we essentially are inefficient. that can be seen with looking at your HR on a run while mouth breathing. I can go out for a run now and cruise at 7:00min pace while nose breathing at a HR of about 120 and if i open my mouth my HR automatically goes up to about 135-140. what Douillard's book says is that with the greater intake of oxygen with mouth breathing there is a greater supply of oxygen and with that greater supply, our heart is taxed moreso because it needs to pump more blood through the pulmonary circulation in order to deliver that greater supply to working muscles. Do we need that much? well, i say clearly not from my own experiences. Try it for a month and let me know what you think.

Hey wonderboy during my body building phase of my life I experimented with a diet called "Body Opus". It basically consisted of virtually no carbs during the week. The goal was to go ketogenic ASAP during the week. Monitored via ketosticks. Lots stationary biking and weights during the week followed by a friday of completly (almost) depleting glycogen reserves by going to failure and beyond for EACH body part. This is some of the hardest training I have ever done. Actually I think it WAS the hardest.

The weekend consisted of reolading carbs (read; BOXES of corn flakes w/ GLUMP....water every two (?) hours even during the night) ME thinks it was something about maltodextrin will replenish muscle tissue before the liver (???) which in the subsequent week allowed you to go ketogenic quicker thus facilitating more lipolysis. If you were good you would be ketogenic by monday evening.

What I found was that once I got on the bike and got spinning for about 10 minutes (almost zero energy at this point) I could ride at a fairly good intensity for (what seemed like) ever.

My question is ; Does this have any application to endurance sports as far as training this metabolic pathway. This was the toughest 4 weeks that I have ever voluntarily endured ( I swear the vending machine at work knew my name and called it quite often) and I would not repeat it unless the was some "benefit". If anything you sure would be ripped!

Whattaya think?

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Holy crap! either you are insane or incredibly tolerant of pain. Well, where do i start on this one!?!?! I "Think" that what you did as far as from a body builders perspective, of which I used to also dabble, you were right on the money as far as how to get ripped. Painful as it is, in order to compete in the body building competitions, WITHOUT DRUGS that is, one really has to be aware of what their every move is nutritionally as well as with training. The maltodextrin question: well, by carboloading that quantity of corn flakes will definitely boost carbohydrate stores (Glycogen) in the muscle that is for sure. However, your question as to which tissue will be replenished first... I would think that the Liver would take a large majority of the glucose and store it as it is needed in a big way there as the Liver is THE source for Blood sugar when we need to maintain it. However, if muscle glycogen stores are very low such as during your "dieting down" phase the muscle will store a large amount of glycogen but remember that with Glycogen storage comes water as well. with each gram of CHO (carbohydrate) about 3 grams of water are stored as well so the swelling and the ripping effect is a result of that swelling.

as far as why you felt good after a few minutes on the bike during your Fast, which is essentially what you did here, you were working out at an intensity where fatty acid metabolism was efficient BUT also obligatory because you had nothing else to burn except for muscle protein which no doubt was utilized as well. some studies by a man named Lemon et. al. have shown that endurance/ultra endurance events can force the body to utilize up to 17% of its calories from Protein sources.

as far as endurance applications... well, beyond developing your pain threshold i would not suggest this method of cutting weight for a triathlon. the primary fuel source for any endurance activity is glycogen plain and simple. However, we can increase our bodies ability to utilize fatty acids efficiently with training therefore reducing the burden of the body to utilize only glycogen which are in limited supplies. Fatty acids are essentially unlimited and ubiquitous in our bodies so if we are efficient at burning them we have a fuel source that will sustain us for a very, very long time. I have heard and have experienced ways to increase fatty acid utilization one of which is to work out in the early morning hours before you eat. This is mentioned in the Douillard book as well if you remember. Caffeine consumption also helps with lipolysis as well. as far as how to enhance the metabolic pathway to increase your ability to burn fat efficiently for Triathlon... good old consistent training!

Thanks for clearing that out, I knew that given enough rope you would hang yourself.

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"Yeah, no one likes a smartass, but we all like stars" - Thom Yorke


smartasscoach.tri-oeiras.com

hang myself? Ha Ha

Your pace doesn't change, therefore I'll assume your economy and ATP demand doesn't change. We'll assume stroke volume doesn't change from one minute to the next and it's probably safe to assume that at sub max, sustainable intensity levels O2 consumption tracks pretty close to linearly with HR. The more 'aerobic' your effort (i.e. the more that required amount of ATP demand is produced aerobically), the greater the O2 required to produce a given amount of ATP (chemistry and thermodynamics).

Therefore, couldn't one conclude that your effort at 120 bpm is more 'anaerobic' than your same effort at 135 bpm? What am I missing?

And who cares whether your heart is 'less taxed'. We're talking comfortable, sub max intensities here.

Have you read this guy's other stuff? It's so bad that Captain PubMed won't even bother, LOL...

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"Yeah, no one likes a smartass, but we all like stars" - Thom Yorke


smartasscoach.tri-oeiras.com

Well, he goes by the name of 'Wonderboy'.

At least we can conclude that he doesn't have any issues with his self esteem.

SAC wrote, in reference to WB's posts: Have you read this guy's other stuff? It's so bad that Captain PubMed won't even bother, LOL...


Don't want to hurt anyone's feelings, but, I know what you mean. OTOH, even though I followed the Capt'ns protocol by citing supporting scientific literature from the "Hallowed PubMed" library, he doesn't respond. Neither did JustCurious, although he's one of the barb-throwers, as are you, SAC, and you both are still monitoring this subject.

Maybe the Capt'n is too busy, or maybe it is too hard for him to say something like..."OK, I see you are talking about right heart function as it affects left heart function, and I was focused on left heart function, I see what you're talking about now." I know he was focused on left heart function, that's why he mistakenly made the comments about pulmonic valve closure and transmural pressures. I agree intrathoracic pressure changes don't have nearly the effect on left heart function beat-to-beat as intrathoracic pressures affect the right heart...but, anyone that has observed PCWP changes due to respiratory variations in people with a Swan-Ganz-type catheter wedged in a pulmonary artery can tell you: intrathoracic pressure does affect left ventricular function to some degree vis-a-vis end-diastolic LV pressure and volume. However, that's not the mechanism to which I was referring in regards to intrathoracic pressure changes and heart function. Direct LV effects due to changes in intrathoracic pressure are probably not significant in a mildly-moderately exercising athlete anyway...at least, not compared to right heart function. It's the right heart that must be considered in this model.

After all, the Capt'n couldn't even bring himself to apologize for suggesting Kraig Willet should sue me, because the Capt'n didn't realize I was simply quoting Mr. Willet....best the Capt'n could muster was something like, "I didn't know Kraig said that, I didn't read the whole thing." Classy...Not.

Whatever, guys. This stuff isn't that important. It isn't mainstream thinking to most people. Even medically-bent people don't always have the habit of looking at right heart function much...they're too caught up in left heart function only. I ran this whole idea by 4 different cardiologists (one that specializes in exercise testing), and 2 heart surgeons....all 6 of them agreed with my assesment of what was going on with HR and "nose breathing". I certainly haven't seen anything by the Capt'n, nor PubMed, nor anyone else to refute my statements about how it affects the HR (although I certainly don't think some of the other posters have the ideas and/or mechanisms correct!)

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Quid quid latine dictum sit altum videtur
(That which is said in Latin sounds profound)

I was talking about wb's stuff, not about the whole concept of "nose breathing". Someone that doesn't understand the simplest mechanisms, talks about lactate clearence and then goes on saying he's a coach kind of ticks me off...

Anyway, from what I read, your proposed mechanism is a bit far-fetched. If the mechnism is far-fetched, it won't be researched anytime soon, so I'm guessing we'll never know :-)

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"Yeah, no one likes a smartass, but we all like stars" - Thom Yorke


smartasscoach.tri-oeiras.com

Pretty much sums up my feelings on the subject.

That said... You seem to have done a lot of meaningless work proving that intrathoracic pressure changes do affect heart function. You haven't proved that breathing through the nose significantly affects intrathoracic pressure.

Kinda like Frank dwelling on how PC's, without a doubt, promote circular pedaling when no one seems to be able to prove that circular pedaling is better.

The WB guy states his qualifications, exercise phys. masters, Pro triathlete etc..Please again state yours so I can evaluate.

Who are you?

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"Yeah, no one likes a smartass, but we all like stars" - Thom Yorke


smartasscoach.tri-oeiras.com

JustCurious wrote: You seem to have done a lot of meaningless work proving that intrathoracic pressure changes do affect heart function. You haven't proved that breathing through the nose significantly affects intrathoracic pressure.


It's not "a lot" of work, it's stuff I already knew from my background. It's not "meaningless" when this knowledge helps you understand, diagnose, and recommend appropriate treatments for conditions found in my line of work. If you don't believe a person can significantly affect intrathoracic pressure by breathing with sufficient effort through a "more restrictive" route, i.e., the nose compared to an open mouth, you know precious little about something as basic as elementary Swan-Ganz-type catheter information, in addition to not much about requirements as simple as those required to begin weaning a patient from a ventilator.

This isn't a PC vs. non-PC topic, and they are not similar. PC vs. non-PC is much more of a guess and opinion based upon very little relevant scientific data. If it seems similar to you, that doesn't make it so...it just shows you don't have a working knowledge of some fairly simple (at least, it's simple to those of us that use it on a regular basis) cardiovascular/respiratory inter-relationships....no big deal if you don't know this stuff, as long as you don't have patients depending upon you to know it, get it right, and do the correct thing to address a problem with the system(s). Nope, not like PC vs. non-PC's at all, Doctor.

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Quid quid latine dictum sit altum videtur
(That which is said in Latin sounds profound)

Im an interested reader who would like to evaluate something that seems interesting, that being said, will you fill me in on your background?...coach.

Check my website dear colleague :-)

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"Yeah, no one likes a smartass, but we all like stars" - Thom Yorke


smartasscoach.tri-oeiras.com

Dude, You may want to switch to decaf...

JC wrote: You may want to switch to decaf...

At least that's something you are qualified to suggest. What I'm going to do is switch to something other than Slowtwitch...not that anyone will care, nor should they.

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Quid quid latine dictum sit altum videtur
(That which is said in Latin sounds profound)

Captain Pubmed wrote: Do you really think I owe you an apology for something as innocuous as that?!?

I'm certainly not going to hold you to that high a standard...and I won't hold my breath (pun intended) waiting for you to do so.

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Quid quid latine dictum sit altum videtur
(That which is said in Latin sounds profound)

Yaqui, looks like you've been testing that nose breathing a bit too much :-) take big breaths, exhale through the mouth while thinking CALM... :-)))

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"Yeah, no one likes a smartass, but we all like stars" - Thom Yorke


smartasscoach.tri-oeiras.com

Captain Pubmed wrote: Here is a simple question for you: what is the magnitude of such changes, and how do they compare to the increase in central venous pressure that occurs during upright exercise at, say, a rate of oxygen uptake of 3 L/min?

Here you go again, trying to change the problem. In a "normal" 70 kg man, exercising at that rate of O2 consumption is out of range of what I explicitly detailed in the original problem. You are right, the task to educate me IS too herculean a task, even for someone as brilliant a professor as you.

Good day. Continue to have a curmudgeondly life, if you like.

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Quid quid latine dictum sit altum videtur
(That which is said in Latin sounds profound)

Thanks, looks good to me;)

I suppose that with ALL those "certifications" you assume that you have learned the correct mechanisms for metabolism of all substrates during physical activity? I do not have time for people such as yourself attempting to belittle others. As far as "hanging myself" as you so arrogantly wrote, I suggest that you pick up an exercise physiology book written by someone other than yourself, actually read it and then get back to me with something educated to say.

On another note... I was not attempting to get into a pissing match with anyone on this topic. This is a FORUM and with that comes sharing of information and the actual possibility that one may learn something new. God knows that i have learned more than my fair share while reading the others supremely thorough explanations of intra thoracic pressure changes associated with nose breathing and whether or not it affects it at all. "Learning" my good man is what life is all about but I guess a man such as yourself already knows it all so just go on thinking that way. Oh, and by the way, I hope to see you at the races!

J Appl Physiol. 2000 Dec;89(6):2196-205. Related Articles, Links
Plasma lactate concentration and muscle blood flow during dynamic exercise with negative-pressure breathing.

Kamijo Y, Takeno Y, Sakai A, Inaki M, Okumoto T, Itoh J, Yanagidaira Y, Masuki S, Nose H.

Department of Sports Medicine, Research Center on Aging and Adaptation, Shinshu University School of Medicine, Matsumoto 390-8621, Japan.

This study assessed the hypothesis that increasing cardiac filling pressure (CFP) would enhance contracting muscle blood flow (MBF) by stretching cardiopulmonary baroreceptors and attenuate the increase in plasma lactate concentration ([Lac(-)](p)) during dynamic exercise. Continuous negative-pressure breathing (CNPB) (-15 cmH(2)O) was used to increase the CFP by accelerating the venous return to the heart. In the first series of experiments, 10 men performed a graded exercise seated on a cycle ergometer with (N1) and without CNPB (C1). The increase in [Lac(-)](p) for N1 was attenuated at 60%, 90%, and 100% of maximal exercise intensity compared with that in C1 (P < 0.001). Also, the increases in mean arterial pressure (MAP) and plasma catecholamine concentrations were attenuated in N1 compared with those in C1 throughout the graded exercise (P < 0.05). However, heart rate and pulse pressure were not significantly influenced by CNPB. Second, we studied the impact of CNPB on forearm MBF during a rhythmic handgrip exercise in 5 of the 10 subjects. Forearm MBF was measured immediately after cessation of the exercise by venous occlusion plethysmography at rest, 30%, 50%, and 70% of maximal work load (WL(max)) with (N2) and without CNPB (C2). Forearm MBF and vascular conductance for both trials increased with the increase in intensity, but forearm skin blood flow measured by laser-Doppler flowmetry remained unchanged. MBF and vascular conductance in N2, however, increased more than in C2 at every intensity (P < 0.01) except for MBF at 70% WL(max), whereas the increase in MAP for N2 was attenuated compared with that in C2 (P < 0.05). Thus augmented active muscle vasodilation occurred in N2 with a lower increase in MAP compared with that in C2. These findings suggest that the stretch of intrathoracic baroreceptors, such as cardiopulmonary mechanoreceptors, by CNPB increased MBF by suppressing sympathetic nerve activity. The attenuation of the increase in [Lac(-)](p) might be caused, at least partially, by the increased MBF.

PMID: 11090568 [PubMed - indexed for MEDLINE]

Generating a greater negative pressure in the thorax increases venous return (in upright exercising humans)...which increases the diastolic volume and therefore stroke volume of the right ventricle, which will show up quickly as increased end-diastolic volume in the left ventricle, increasing SV. Note that they found insignificant effect on HR. Note also, that they exercised rather vigorously. The effect on HR is transitory, although real, and equilibrates fairly quickly (30-45 seconds, up to maybe a minute), so, is insignificant...which is what I stated.

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Quid quid latine dictum sit altum videtur
(That which is said in Latin sounds profound)

I wrote: The CVP isn't so high during exercise that forcibly increasing negative intrathoracic pressure (by sucking in through your nose, for a specific example) has no effect on venous return.

Capatin wrote: Prove it.



That article supports the position I stated. It doesn't prove it. It also says the change in HR is insignificant, not that it doesn't have an effect. My explanation of the slight change in HR (which does occur, even if it is not a "significant change) and the reason it re-equibrates within a minute are what I suspect you never bothered to read.

Fine with me to close the case, we both agree it is insignificant in the long run. But, when you say negative intrathoracic pressure doesn't have an effect on venous return, even during exercise, I disagree. The venous system is a capacitance system, and this system, when driven from a remote pump (left ventricle), even if there is assistance from venous tone, splanchnic volume, muscle "pump", one way valves in the lower body, etc., the total flow in the inferior vena cava can be increased by manipulating intrathoracic pressure as little as -15 cm H20. The fact that one criteria for weaning a patient from a ventilator is the ability to generate at least -20 cm H20 pressure, -15 isn't hard to do, it's relatively easy.

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Quid quid latine dictum sit altum videtur
(That which is said in Latin sounds profound)

The paper stated:

Continuous negative-pressure breathing (CNPB) (-15 cmH(2)O) was used to increase the CFP by accelerating the venous return to the heart.

So, I should have said the "author agrees with me" about CNPB accelerating venous return to the heart, rather than the paper "supports" this theory...if you read my next sentence, I said that this paper doesn't prove the theory, just states the theory as fact, which it is. A fact. A fact you continue to say doesn't exist. I, make that, we, disagree. So do the researchers with whom I worked with on artificial hearts two decades ago...yes, exercising people's needs were being considered in artificial heart research way back then.

I assure you, increasing the negative intrathoracic pressure augments extra-thoracic venous return in exercising athletes. If you don't believe it, for whatever your reasons, it's no skin off my nose. Apparently, you have precious little experience in this area. I certainly have zero aspirations of trying to bring you up to speed in this area other than to tell you to think about it. And no, I won't provide lab data proving my position...the data belongs to the artificial heart research team(s).

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Quid quid latine dictum sit altum videtur
(That which is said in Latin sounds profound)

their data do not support the theory that breathing against negative pressure increases venous return,

Breathing against negative pressure? What are you talking about? That makes about as much sense as your off the path comments about pulmonic valve and transmural pressures in this matter...none.

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Quid quid latine dictum sit altum videtur
(That which is said in Latin sounds profound)

This whole thread really baffles me.

Let me summarize...

Breathing through the nose may be a significant way to induce CNPB.

CNPB may accelerate venous return to the heart.

Improved venous return to the heart may lower heartrate slightly at a given, sub max exercise intensity.

A slightly lower heartrate at sub max exercise intensities offers no tangible benefit.

This thread is worth reading because????

JustCurious wrote: Let me summarize...

Breathing through the nose may be a significant way to induce CNPB.

CNPB may accelerate venous return to the heart.

Improved venous return to the heart may lower heartrate slightly at a given, sub max exercise intensity.

A slightly lower heartrate at sub max exercise intensities offers no tangible benefit.

This thread is worth reading because????


You and I agree on all of this. (One thing you left out was that any effect on HR is transient, because a new equilibrium is established between LV output and RA return in probably less than a minute. I knew you and I couldn't be THAT far apart.)

I think this is worthless reading to most anyone. However, the Captain is wrong about several things here, and he can't see it or won't admit it or doesn't know it, so, since I'm tapering and not working today, I'll play along as much as he can stand. Everyone knows it won't accomplish anything, the Captain can't be mollified.

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Quid quid latine dictum sit altum videtur
(That which is said in Latin sounds profound)

the captain wrote: obviously I meant breathing with continuous negative pressure

There ARE things that are obvious about your posts...however, what useful information you attempt to convey with your posts isn't always so obvious. Do you realize this is the closest I've ever seen you come to admitting a mistake? The pain you feel may be personal growth...but, again, I won't hold my breath (pun intended, again).

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Quid quid latine dictum sit altum videtur
(That which is said in Latin sounds profound)

I am reading, Mind, Body, and Sport, by John Douillard. I received it for Christmas. When I searched the forums for Douillard this was the only thread I got. Does anyone have some input on this book/techniques? The thread itself seems to have gone up in a ball of nothingness.

Just following along here. Interesting to read, not really sure what to make of it all. Let me ask a question of you.

Why is this discussion centered so much around oxygen and not CO2? The air you exhale still have a lot of oxygen in it - more than the air you inhale when you do altitute training in, say, the mountains of Colorado. The urge you get to breath when you finish that last hypoxic 25 or 50 yard swim isn't to get oxygen, it is to get rid of CO2.

Doesn't this nose breathing really limit the ability of your body not to get oxygen (particularly at sub-max/moderate intensities) but limit your body's ability to get rid of CO2?

It is extinct because it isn't interesting to most people.

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Quid quid latine dictum sit altum videtur
(That which is said in Latin sounds profound)

Well, you're mixing things here. The O2 present in expired gas from human lungs at sea level can have more oxygen in it than the ambient air at altitude (if you are referring to the number of molecules of oxygen found in the total volume exhaled, although of course, the percentage of O2 in the exhaled air is certainly lower than the percentage of O2 in ambient air in Colorado). I would say that if you are in a hypoxic state, there is an added drive sent to your respiratory muscles to increase ventilation...although you are correct to state a rising CO2 level is the primary stimulus to increase respirations...unless you are a chronic CO2 retaining person...then, your cerebral spinal fluid has so much buffering capacity from the years of retaining CO2 that the CO2 drive is severely attenuated, or, is not even functioning compared to the O2 receptor drive. But, this has little to nothing to do with athletes.

I think to answer your question, the reason people usually talk about Oxygen rather than CO2, is that CO2 moves across membranes much more easily than O2, another way to say it: it takes much less pressure gradient to drive CO2 across a membrane compared to 02, so, gas exchange limits are usually of O2 transfer, not CO2 transfer.

The reason the discussion got so involved, was; there were some false statements concerning intrathoracic pressure changes affecting venous flow rate toward the right atrium....intrathoracic pressure can affect venous flow, even during exercise....again, the effects are transient, as a new equilibrium is reached.

Man, you two dug up an oldie....

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Quid quid latine dictum sit altum videtur
(That which is said in Latin sounds profound)

My experience comes from my graduate degree in in industrial hygeine and work experience in personal protective systems such as respiratory fit testing and SCBA training.

Here is some food for thought I found while looking into some of my old stuff from school (not my research, but the research of others):

Your lungs are two large sacks that are tapered toward the top and quite wide at the bottom. They are filled with alveoli, small sacks filled with capillaries (tiny blood vessels) that allow carbon dioxide to leave your body and oxygen to enter. Not only are the bottom portion of the lungs larger, they also have a much higher number and concentration of alveoli than the top portion. When you breath shallow breaths through your mouth, you are not utilizing the lung’s maximal oxygen processing capabilities.
When you breath in through your nose, the air flows over the turbinates, which directs and funnels the air stream more effectively to the lower portions of the lungs.

Let’s take an example of a runner. When you mouth-breath while running, you are taking in rapid breaths of large volumes of air. The result is that your body is able to throw off large quantities of carbon dioxide, a waste-product of the body. This is good right? Well, yes…..but only to a certain degree. The problem is, mouth breathing quickly puts people into a state where they create an artificially low concentration of carbon dioxide in the bloodstream. With low quantities of carbon dioxide in the blood, oxygen is not released as freely into the cells of the body. The body is tricked into thinking it is hyperventilated, or already has enough oxygen! The body needs to maintain a certain level of carbon dioxide in the blood to maxmize its ability to absorb oxygen from inhaled air.

It is like trying to fill up a small cup of water from a fire hydrant. With the water gushing so fast from the hydrant, there would be no way to get anything into your cup! Despite the higher volume of air inhaled through the mouth, your body is actually getting less oxygen. This is counter-intuitive, but makes sense when you study the underlying biological process.
Breathing through your nose allows a smaller and more highly directed stream of air to flow deep into the lungs. As a result, according to Dr. Konstantine Buteyko (creator of the The Buteyko Breathing Technique), the carbon dioxide levels of your blood are able to stay at a more moderate and even level, and the oxygen is able to be efficiently absorbed into the bloodstream.

As an added benefit, the nasal sinuses are large producers of nitric oxide, which is a powerful vassodialator. It’s presence signals blood vessels and capillaries to relax, thereby increasing blood flow to your cells.

I subscribe to the method of breathing to INHALE through the nose and exhale with vigor through the nose and mouth.

I started teaching spin classes this fall and I try to explain my reasoning to the athletes before I start with them and then leave it up to them to figure out the degree to which they wish to try and use the method.

Cheers,

Dave

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Dave Stark
dreamcatcher@astound.net
USAC & USAT level 2 certified coach

This is 100% correct
It isnt the oxygen that regulates breathing, its carbon dioxide. Your breathing rate goes up when you increase intensity in an attempt to rid the body of more Co2, not get more oxygen in.