Reverse packing and contractions

[m2b]

Reading the previous thread on reverse packing and doing a little bit of it yesterday evening brought on one big question. If you normally get contractions with breathhold diving should you also be expected to get contractions with reverse packing. Reading the link thread that was included in the previous thread a couple of days ago made it sound like you was essentially guaranteed to get contractions.

I know fear(normally would be called 'mind') over matter hasn't even allowed me to get to the point of contractions. The fear sets in and I'm up and breathing probably long before contractions would set in. Since I'm out there by myself, the fear factor is my best friend, very admittedly. I'm just asking from the knowledge standpoint of things.

Also why is it that I can hold my own underwater with a exhale/reverse pack without the sudden urge to breath that I get while trying it right in front of the computer. In front of the computer the urge is so strong right after about the second reverse pack that I must breathe. There isn't any chance at all to be able to hold it any longer. Yesterday in the water, two feet deep or six feet deep, the urge wasn't there even after 10-15 seconds. I didn't get anything other than fear creeping up in my system.

Thanks,
Ryan

 

[naiad]

I also find it much more difficult to hold my breath on an exhale out of the water than in the water, I don't know why. I can't bear to do it to the point of contractions!

It is VERY important to have someone with you if you are doing any training in the water, and even more so with exhale training.

Lucia

 

[fpernett]

Ryan
I think the main use of reverse packing is to deal with pressure changes. I use it just to simulate deep diving, because I'm too far from deep waters. So, I don't try to do long bottom times, I work to equalize and accustom to chest pressure increasing the number of reverse packs. It's very easy to BO!!. I reccomend you to work forward to increase the reverse packs and not on bottom times, and always have a good partner with an eye on you.

 

[m2b]

I'm pretty much the same way. Both the lakes/ponds that I have around me are pretty much shallow bodies of water. At least where I would be willing to do any diving. I don't play with motor boat traffic, I'm too small to stand a chance against them.

Since I only have regular swim goggles, that pretty much keeps me from going much more than 10-12 feet down. I usually am only under 10-15 seconds at a time, even on inhale dives. I could go much longer, if I even tried but I haven't even bothered really trying. I haven't did any regular packing or any real deep breaths before diving. No trying to stay relaxed or anything like that either. Since I'm planning short dives, depth and time I don't worry about it too much. Granted anything can happen.

Around where I live it is a little difficult to find anyone that does any freediving. I've been reading on the forum and the main site for three or four years now and I have seen a few people from NH post requests for partners, to have nothing come back in return. This area just isn't well known for it. You have to get 2-3 hours away before you find the Boston/Providence coastline and anyone that does any diving. With gas prices, I stay close to home to do pretty anything I'm involved in. Why travel when you don't have to. I used to spend all my time in the pool, now I'm still getting used to the concept of open water swimming/diving. Hence, why I play it safe and don't spend much time underwater.

I was mostly just asking the question out of curiousity more than anything else. Kinda call it the safety factor. Knowledge is far better than ignorance. You can have all the safety around that you could ever hope for and still be ignorant. The safety doesn't stop you from still ending up dead. I decided to ask the question to make sure on what I've read.

Now that I'm thinking through what I read last night a little more carefully, I think I want a good answer to the question even more so now. Is it not the CO2 buildup that causes you to get the contractions in the first place?

Two scenarios, same divers in each scenario, both times they have the same exact amount of oxygen in their system:
Dive 1. Normal dive, let's call it limited inhale
Dive 2. Reverse pack dive

In the second case the diver wouldn't get the contractions as early as he did during the first dive...correct? Again, it takes the CO2 buildup to cause the contractions and it would take longer to get the buildup in dive 2.

At the same time, has anyone ever not gotten contractions when reverse packing? That was the main point that I was trying to get at with the post, I just didn't come right out and say it like a dummy.

Thanks,
Ryan

 

[fpernett]

Well, I don't think that the two scenarios could have the same amount of oxygen. When you reverse pack, you are taking your lungs below Residual Volume (RV), and for most of us (inhale freedivers) the main store for oxygen is the lung, so in a Reverse Pack Dive you have low stores of this gas.
When talking about the contractions, or the urge to breath, what is most important is CO2 concentration than body stores. If you don't hyperventilate, the CO2 concentration after a Reverse pack can be the same as an inhale dive. It's possible to don't have contractions after a strong hyperventilation, but the Oxygen levels will fall down without any notice (if you are static) that you will Black-Out before having contractions.
That was your point? Or I'm missing something?

 

[m2b]

Kinda. I've always heard the same thing about being able to BO and 'not knowing it' after hyperventilating. That's why I wouldn't even consider doing that. It's just way to dangerous.

Is it possible, without hyperventilating beforehand, to BO after reverse packing WITHOUT having contractions? This figuring a normal person and not a top notch freediver that has trained his body to the point that he never gets contractions on a normal dive.

When you exhale you blow out CO2. I thought reverse packing reduce both CO2 and O2 stores in the lungs? Wouldn't that make any contractions come much closer to the BO point after reverse packing then otherwise? Does it also make the first contraction stronger on a reverse pack dive then on an nhale dive.

In the previous two dive example wouldn't the diver on a normal breath have far more contractions before BO than the diver after reverse packing?

Yeah, I am making this sound confusing ain't I. Sorry.

Ryan

 

[fpernett]

Is it possible, without hyperventilating beforehand, to BO after reverse packing WITHOUT having contractions?

YES, I think is possible. The contractions are related with CO2 concentrations and pH changes also. The respiratory center is quite different from one person to another some people (like native highlanders) have a blunted response to CO2. So you can have a very low level of O2 before you get warning from CO2 or low pH

When you exhale you blow out CO2. I thought reverse packing reduce both CO2 and O2 stores in the lungs? Wouldn't that make any contractions come much closer to the BO point after reverse packing then otherwise? Does it also make the first contraction stronger on a reverse pack dive then on an nhale dive.

YES, as I told you before both stores are reduced, but not exactly the blood concentration. In a reverse pack I'll never wait to have contractions, in an inhale dive you can have a lot of contractions before surfacing, because the contraction only tell you to breathe, but in an inhale dive you know of what you are capable to, so you can hold it for a while. In a reverse pack the Oxigen level is very low, and fighting the contractions will make you to BO. Always in an inhale dive you can have more contractions than in a exhale dive. That's why I don't hyperventilate, in fact I hypoventilate in reverse pack dives, and have a partner all the time.

 

[waxlips]

i reverse pack and get contractions powerful ones and go a long time like this. i put a tight mask over my face to prevent me from breathing in.