Lung stretching

[baiyoke]

A question about doing the stretch after exhale and perhaps negative pack, the uddiyana bandhas excercise...

The diaphragma I imagine is pulled upwards, stretching it... So why are people doing the abdominal crunching. Wouldn't it be better to just suck and pull the stomach in. As I picture it, crunching the abs will just pull the diaphragma down again to a more neutral position... That will perhaps work on the "throat flexibility" (whatever that is exactly), but people seem to look at the abdominal crunching as a diaphragma stretching excercise, wich doesn't make sense to me...

Can somebody clarify...

Second question: Will the "negative upward stretching" also have a positive effect on the downward flexibility, and thereby make greater lung capacity possible?

 

[RPGgrenade]

I can only kinda answer the second one: I usually do belly breathing to work on the downward flexibility of the diaphragm, but the uddiyana bandha usually works it pretty well, too. Particularly because you're at least stretching it.

 

[Will]

First question: abdominal contractions whilst maintaining diaphragmatic introflexion (uddiyana bandha) will convert the negative intrathoracic pressure into thoracic compression (collapse of rib cage) and rigid airway compression, both of which are required to tolerate high ambient pressure during deep dives.
Second question: Yes, perhaps a little, but this effect isn't as important as being able to introflex further up under the thorax, compensating for the loss of pulmonary volume during a dive.

 

[baiyoke]

Ok, thanks for the answers. That's very clear now: The negative pressure stretching is first and foremost aimed at negative pressure tolerance, but might have a (small) effect on lung expansion stretching also.

Additional question about the negative pressure stretching:

In the pool I exhale, and negative pack until I have only just enough air for a tiny mouthfull for equalising, then submerge to app. 4,25 meters. I have no problem doing that, except I feel tension/pressure around the throat.

At 4 meters there should be app. 0.71% volume according to my calculations. So I would think it made a difference being in a pool, compared to sitting on land doing the same. Squeezing a little extra. But it doesn't feel any more difficult.

My question is: Could I do the excercise on land, getting the same stretch, in a much safer enviroment - and being able to do it more often. Or do you think the 0.71% does something extra...?

Can you feel you are close to your stretching limit? Or is it like BO, that you only recognize it when it's too late..?

 

[Simos]

What is the 0.71% volume???

 

[growingupninja]

Can you feel you are close to your stretching limit? Or is it like BO, that you only recognize it when it's too late..?

You can be injured from overstretching so I that would be one 'limit' to consider, but also you have a ticking clock anytime you are neg packed. Since there is not much air in the lung your body will be using the O2 in your blood right away and you will run out of O2 before CO2 levels become uncomfortable. It would vary greatly among individuals but for instance if you could do a 6 min full lung hold before samba you might not make much more than 2 mins neg packed before O2 levels are dangerously low. If you are stretching, ypur muscles are working so that would further eat up O2 and reduce your time.

I am also pretty sure if you neg pack at the surface and drop to the bottom of a pool, if you were to black out you would stay on the bottom and the negative pressure would suck water into your lung; bad news--even if you were rescued before drowning water in the lung is hospital time.

 

[baiyoke]

What is the 0.71% volume???

He he. That is the volume of a specific amount of air at 1398 meters depth :blackeye

I meant 71% of surface volume...



growingupninja --> Thanks for the info and warnings ... I'll take that into account.

Just for the record I'm only staying down there for 10-20 seconds... Perhaps a bit short for stretching anyway...

 

[baiyoke]

a) My question is: Could I do the excercise on land, getting the same stretch, in a much safer enviroment - and being able to do it more often. Or do you think the extra pressure at 4 meters does something extra...?

b) Can you feel you are close to your stretching limit? Or is it like BO, that you only recognize it when it's too late..?

Anyone on this??

 

[growingupninja]

a) My question is: Could I do the excercise on land, getting the same stretch, in a much safer enviroment - and being able to do it more often. Or do you think the extra pressure at 4 meters does something extra...?

b) Can you feel you are close to your stretching limit? Or is it like BO, that you only recognize it when it's too late..?

Anyone on this??

What do you mean stretching limit? The point at which you are suffering some kind of pressure squeeze? I think it is probably hard for anyone to answer; negative pressure situations in water whether they are from very deep full lung dives or being neg packed in a pool are dangerous. It would depend on your total lung capacity, but a forced exhale plus possibly neg packing at the surface, folllowed by a drop to 4m would simulate for most people pressures of a full lung dive to 200+ feet. As far as stretching limit due to low O2 blackout, it would be much easier to cross this threshhold when stretching on an exhale because you won't get a strong CO2 warning signal. Low O2 without high CO2 is not particularly uncomfortaable, although massive vasoconstriction and brachycardia may feel strange when it first comes on. I know my body adjusts quickly to the sensation though (within maybe less than a minute), and with continued exhale work I will feel pretty good even though my blood O2 sat is in the low 80's, etc. If you want to play with this a pulse O2 sat meter might be useful--you can use it on land and get a better sense of what is going on. Results would probably surprise you. Youtube some video of pilots in altitude chambers where they are being gradually subjected to dcreasing O2 levels.. They are breathing normally so there is no CO2 build-up.. They are pretty comfortablebut have gradually diminished mental capacity until they can no longer put on an O2 mask even with a guy standing in front of them saying 'put your mask on. If you don't you will die.'

 

[baiyoke]

What do you mean stretching limit? The point at which you are suffering some kind of pressure squeeze?

Yes, exactly that.

Thanks for the answer.


The question relates to stretching, and not to BO/o2/CO2 when negative packing - but thanks for the info anyway, very interesting.

a forced exhale plus possibly neg packing at the surface, folllowed by a drop to 4m would simulate for most people pressures of a full lung dive to 200+ feet.

Wow. Seems like I might have been fooling around a bit too much then. BUT I feel I've have been taking it very gradually over perhaps three months twice a week, from just exhale to forced exhale to 5 and later 10 negative packs. Is's not that big a deal at 4 meters, and that's why I'm asking if a squeeze comes with (many) warning signs, or just comes suddenly when pushing it perhaps only a little more than last time... Because I know that exhale dives are harder to control/regulate... going just a little deeper can make a big difference in lung volume.

 

[watts]

Just progress slowly and listen to your body. Very regular stretching over a long period of time makes a huge difference. Not only uddiana but great torso flexibility. If doing exhales on a line dive descend slow and with cauition ready to grab the rope to stop decent. You have to wait for the bloodshift which will increase in speed over time. I really enjoy full exhale dive and the sensations associated. I recently got to the point where I feel little to no pressure at all.

 

[alonrivkind]

Hi baiyoke,
I think its big different doing the neg pack stretch outside and inside the water. if you full exhale (maybee 1 or 2 neg pack) lets say you start the dive with 1.5 liter(RV)-when you reach 10 m you have 0.75 liter, the blood shift happens quickly. much more pressure.
I use to do many negative dive, always with caution, each dive the pressure fill easier.never had squeese doing it, but i never wait for contractions to come.