Breath control techniques?

[OceanObsessed]

With all due respect, you are changing the subject without resolving the accuracy of your original statement.

As to your hypothesis that prolonged breathhold cases diaphragmatic contractions which in tern cause brachychardia (and note that all brachycardia is not mammalian diving reflex) would you be so kind as to supply a reference from a peer reviewed journal that substantiates that claim?

Sure thing Thal. Here is a quote from a publication from the Journal of Applied Physiology: Diving reflex in man: its relation to isometric and dynamic exercise.

This so called Diving reflex is elicited in part by apnea and in part by reflexes from nasal and facial receptors sensitive to cold water (1).

And here is a quote from a book entitled Exercise Endocrinology.

Diving reflex consists of bronchoconstrictions and supression of the Q and respiratory drive in response to face cooling and breath holding during swimming or exposure to cold air( Kawakami at al 1967; Smith et al 1997) It is initiated by the rise in pCO2 and fall in pO2 during breath holding, is subordinated to diving reflex through interactions between the neurons in the Botzinger complex and the RVLM nucleus that initiate and time respiratory and cardiovascular functions.

 

[scubadown1616]

good stuff..

 

[Thalassamania]

Sure thing Thal. Here is a quote from a publication from the Journal of Applied Physiology: Diving reflex in man: its relation to isometric and dynamic exercise.

Interesting article, two real points: there can be a very mild brachychardia associated with breath holding alone, I don't know that I'd go so far as to style it, "mammalian diving reflex" since it is no diving involved and it is no where near as pronounced; also that MDR is "more" pronounced when the subject has an elevated heart rate due to exercise (implying to me that perhaps MDR aims at a taret rate rather than just producing a particular absolute or relative drop ... now that's fascinating.

And here is a quote from a book entitled Exercise Endocrinology.

Perhaps I missed it, but neither address diaphragmatic contractions or the idea that multiple repeated breatholds with immersion seems to have a positive influence upon breath hold time and comfort until fatigue or chilling sets in (which I thought was topic on the table).

 

[OceanObsessed]

Interesting article, two real points: there can be a very mild brachychardia associated with breath holding alone, I don't know that I'd go so far as to style it, "mammalian diving reflex" since it is no diving involved and it is no where near as pronounced; also that MDR is "more" pronounced when the subject has an elevated heart rate due to exercise (implying to me that perhaps MDR aims at a taret rate rather than just producing a particular absolute or relative drop ... now that's fascinating.

I thought the only thing in question was whether or not breath hold can elicit the diving reflex in humans .

Referring to Table 1 in the journal, I would say that the breath hold component is approximately equal to the immersion component. Example: For the moderate bicycle exercise data: the dry breath hold dropped the HR by 23 beats per minute. The wet breath hold dropped it by an additional 21 beats per minute. But remember that the wet breath hold data is benefiting by both the immersion and breath hold component of the reflex.

If you want to further compare the breath hold component of the reflex with the facial immersion component there is a more recent journal (and its free) that does exactly that. See Cardiovascular and respiratory responses to apneas with and without face immersion in exercising humans.

Here is a quote from the journal:

The oxygen uptake from the lungs decreased during apnea in air (-22% compared with eupneic control) and was further reduced during apnea with face immersion (-24% compared with eupneic control) .

This journal seems to suggest to me that the breath hold component has a much stronger affect on oxygen conservation than the facial immersion component. During the study, the facial immersion only lowered oxygen uptake by an additional 2%. This suggests to me that the oxygen conserving affect of the breath hold induced reflex will lead to longer breath holds.

The difference in results between the two journals may be that the first one used medical students as subjects and the other used mostly experienced freedivers. Perhaps the experienced freedivers have a better developed breath hold reflex.

Perhaps I missed it, but neither address diaphragmatic contractions or the idea that multiple repeated breatholds with immersion seems to have a positive influence upon breath hold time and comfort until fatigue or chilling sets in (which I thought was topic on the table).

I think I may have stated something that can be interpreted two ways and perhaps that has caused some confusion. When I stated that "the breath hold causes contractions which then cause immediate bradycardia." I am implying that the breath hold causes the bradycardia, not the contractions. The drop in heart rate typically happens right at the same time as contractions begin, or shortly thereafter. I don't think this is a coincidence but I am not implying that the contractions cause the bradycardia either. You don't need a peer reviewed journal to verify this as most people can witness the drop in HR right around the same time as contractions with a simple heart monitor.

 

[Thalassamania]

Interesting stuff, I learned a few things, especially from Andersson's article. Thanks.

 

[Slonda828]

There is an excellent article on freediving in the August/September 2008 issue of Hana Hou (Hawaiian Airlines). It is an informative piece by Michael Shapiro about his experience taking a freediving class with Kirk Krack. Great read if you can find it. Don't miss the last page, though. Sad little blurb about Sergio Goes (the photog for the piece) and how he died freediving (not trying to discourage, but INCOURAGE).

ALOHA!

Thanks for the "Incouragement".

 

[homerjion]

I know this post is old, and I'm far from an expert freediver, but I thought I'd throw in my two cents. Most of my experience comes from diving in some 30 foot deep hot springs with my brothers over the last few years. In diving there, we learned that a great deal of our ability to hold our breaths was purely mental. The first couple of times we went, we just tried to go all the way to the bottom, even using fins. We never went more than a couple times a year, with no practicing or training in between, so nothing other than self confidence has changed. Now, it is easy to reach the bottom and swim around exploring. When timed, two of us can stay down for 3 and a half minutes at a stretch, with no special breathing techniques.

A word of advice, however, from personal experience:
--Learn your limits and never push them while diving deep
--Always take a sufficient amount of time to recover between dives
--Always dive with a spotter that you know and trust

I recently pulled a freediver from the bottom of a swimming hole and administered CPR after he succumbed to shallow water blackout. His buddies thought he was joking around and they weren't paying much attention. A doctor once told me that the reflex to breath is caused by a buildup of carbon dioxide, not a lack of oxygen. When you dive successive dives without sufficient time to recover, you release enough carbon dioxide, but you don't replace enough oxygen. In that state you can can easily pass out before you ever feel the strong reflex to breath.

Good Luck!