Dive reflex not always helpful?

[Ulf]

BTW naiad, I should mention that most of the divers at the course that I saw do the test didn’t get a 50 % drop in heart rate. More like 30 % or less so what ever you got I don’t think you’re far away from the average diver…

[naiad]

That's a relief, then I am not that much worse than average!

Originally Posted by Ulf

One thing that has been very helpful for me to improve my DR and vasoconstriction is diving in water temps of about 15-18 C. This really kicks in the vasoconstriction especially the lower temps in that range.
For me, pool temps does not seem to influence the vasoconstriction a lot and considering that the body reacts mainly to temperature differences and that those temps are actually higher than room temperature that makes sense. Maybe this could be changed by doing a lot of max attempts in the pool. Teaching the body that pool water means looong breath holds.
I think cold that is uncomfortable is detrimental to performance. I mean shivering or freezing.

For me, anything less than 30C causes shivering and a drop in performance. The shivering starts a few minutes after getting in the water. My best pool statics and dynamics have been done when I am not cold at all. The cool water does cause vasoconstriction, but it also causes shivering and increases O2 consumption. If I could find a way round this problem, it would be a major breakthrough.

[DeepThought]

Lucia, I asked for your breath-up suspecting the same reasoning Trux mentioned in his post. I think that hyperventilation might be getting the better of you.

Originally Posted by naiad

It may be the lack of dive reflex. Even with no breathe-up at all, and therefore no possibility of hyperventilation, my heart rate does not decrease significantly.

From my experience, a long struggle phase does not increase my total apnea time, and the stress increases O2 consumption, decreasing the time I can safely do. I have tried CO2 training, and while it increases my CO2 tolerance and therefore improves my performance, it does not seem to produce any DR.
The drop in heart rate is the same with or without the breathe-up, so I don't think it is to blame for the lack of DR.

This means that your DR is undeveloped now, it doesn't mean that once you increase your CO2 tolerance and train your DR it won't be stronger.

Originally Posted by naiad

Maybe I am an unusual case - I simply don't have any significant dive reflex.

No, I think that as long as you hyperventilate and work AGAINST your DR, and well, everything apnea-science & elite freedivers' experience tells us (that CO2 keeps you conscious and potentiates the DR) I don't think your claims to be an exception can be validated. (not that I think that one should accept our current knowledge base as a fact).
If you had a better CO2 tolerance then your struggle phase was easier. Maybe even easier than the one you experience now. I can assure you hypercapnic apnea can be just as fun or more, if you can handle it.
Getting that CO2 tolerance can be painful though, but working properly/hard enough can show results sometimes in a few days.
Another issue to think about is safety.

Getting cold as fast as you do does sound like an exception though. I remember it was discussed in another thread before to no avail, but I just thought of something - do you think that maybe shivering, or actually feeling cold could actually be a trained response of yours? were you always that extremely sensitive to cold water? maybe a leftover response from when you were anemic?
Have you tried training your mind to accept the feeling of cold water? to even try and enjoy it?
Being in a warm country my cold water tolerance is quite bad, but from the little experience I have I find that my mental state can affect how long I can last in cold water.

[naiad]

I think the shivering and feeling cold could partly be a trained response. Certainly the shivering sets in long before there could be any drop in core temperature. This morning, I had to go outside in heavy rain. I stayed out for only a few seconds, but as soon as I was back indoors, I started shivering.

I don't mind cold water outdoors as much as indoors. This is probably because it is easier to get warm in hot weather or when doing outdoor work than in an indoor pool.

I have always liked outdoor and water-related activities, so I usually approach these activities with a positive attitude, but the cold gets the better of me. Moving around keeps me warm, but as soon as I stop moving, I am unable to maintain a normal body temperature.

I don't remember always being that sensitive to the cold, which is surprising because I used to be much thinner than I am now. It started long before I started freediving, but I don't remember exactly when.

[BennyB]

Eat a couple more pies Lucia, that'll help!

[naiad]

I wish I could gain a bit of weight!

About the breath-up, I think there has been a misunderstanding. I do not always do the breath-up/hyperventilation when training. In fact, I used to always train dynamic with no breath-up, and sometimes still do. Despite training a lot in this way, my performance was never very good.

[naiad]

One of the problems is that when I get into cold water, I get an immediate and very strong urge to breathe in. If my face is in the water, I can resist it, but it is excruciating. I can't remember any other freedivers describing this problem, but it must exist, because apparently one of the dangers of falling into cold water is that someone may lose control of their breathing and drown, even if they are a strong swimmer.

[atomichaggis]

Originally Posted by naiad

One of the problems is that when I get into cold water, I get an immediate and very strong urge to breathe in. If my face is in the water, I can resist it, but it is excruciating. I can't remember any other freedivers describing this problem, but it must exist, because apparently one of the dangers of falling into cold water is that someone may lose control of their breathing and drown, even if they are a strong swimmer.

Involuntary Gasping is what happens to anyone immersed in very cold water.
I went into the fjord for a dip minus the suit in spring when the water was just above its coldest and I had to fight so hard not to inhale water, I was lucky that I had the snorkel in My gob before My head went in. Its at it worst immediately then becomes a bit more manageable as Your body adapts to it but i think there will be temperatures where You have no control whatsoever.

My Uncle who was a strong swimmer drowned in the river Clyde when it was partially frozen over. I think the cold water probably had the final say.

My cousin fell into the river Ouse a few years back in winter and He gasped uncontrollably and quite violently and He was only in up to his chest. He was lucky enough to land on a sloped bank wich held His weight. He didn't even have enough control to get Himself out and had to hauled out by a friend.

[naiad]

Then that is an important safety consideration for diving and other watersports.

What a useless reflex, I don't know how it could possibly be good in any situation to gasp when falling into cold water.

[atomichaggis]

It is rarely good to fall into really cold water.

[naiad]

I don't think there is enough awareness about this issue in diving and other watersports. I can't remember it being mentioned as a safety issue anywhere. I'm sure many accidents must be caused by it, particularly in scuba. A mask flooding, drysuit leaking or falling into water can cause a disastrous situation.

Although I hate cold water with a passion, I have a reasonable amount of self-control because of my apnea training, so I am probably less likely to inhale water than someone with no training. Despite that, I know that if my mask flooded in cold water on scuba, the best I would be able to do is make an emergency ascent. I would not be able to clear the mask, or even to breathe normally.

Another issue is that what counts as 'cold' water varies considerably from one person to another. Some people say that 18c is warm, when for me it is unbearable. Others will complain that they start shivering in 30c water, which for me is warm even if I stay for hours in a swimsuit.

[atomichaggis]

I don't think its a huge issue In diving and other watersports as You take precautions against the cold and you anticipate the shock. Wearing the the requisite thermal protection is just basic stuff and On Scuba at least You got something to breath until Your body adapts in the case of some suit malfunction. Most people who are caught out by the extreme cold are neither adequately dressed for it nor do they anticipate it... or in My case I just overestimated My own tolerance of really cold water, that is really a personal thing. It doesn't seem to bother Mr. Fattah or Fondueset who is good down to 3C when He is not levitating above lotus flowers on a carp filled lake or whatever.

[naiad]

I wasn't thinking about experienced divers, more about new divers who may have qualified abroad somewhere nice and warm, and are not aware of the risk.

Anyone who is diving in 3C water is superhuman.

[atomichaggis]

I was reading some of Mr. Fattahs posts about diving in BC with no suit and the time He spent in the water is incredible. It is said You got around 15 minutes in the water here before you are gone... Maybe science knows nothing and you just gotta get used to it.

[turtle]

atomichaggis - what's with all the capitals on your pronouns? His, Hers, Mine... sorry, It's just bugging Me.

f