Twitching Before Contractions?

[naiad]

I often find myself shaking slightly, only my upper body, during any sort of physical or mental stress, such as being very tired, frightened, stressed, drunk or after long apnea. It is not noticeable to other people, maybe partly because I try to hide it. This started after an operation for sinus trouble which I had a few years ago.

It was definitely caused by the operation, because I never had anything similar before that time, even in very stressful situations. It hasn't got any worse, so I'm not too worried about it.

Although most of the time I find it difficult to keep still, it becomes much easier when doing statics! I hardly ever find myself twitching during any kind of training. In fact, very occasionally during dynamics I relax so much that I lie on the bottom of the pool! :duh

I have noticed that my concentration has improved a lot since I started freediving. Has anyone else noticed something similar?

I didn't know that so many of us at Deeperblue are twitchers - it must make it very hard to judge competitions.

Lucia

 

[Jason Billows]

Hey Bolts.

I think Jason W may be onto something with the theory of hyperventilation causing your twitches.

I seem to remember that during your PB static breath-up you were doing pretty quick exhales, almost purging. While it's not necessarily hyperventilation it certainly was much quicker than your typical breath-up and you probably blew off quite a bit of CO2.

Jason

 

[bolts]

Originally posted by Jason Billows
Hey Bolts.

I think Jason W may be onto something with the theory of hyperventilation causing your twitches.

I seem to remember that during your PB static breath-up you were doing pretty quick exhales, almost purging. While it's not necessarily hyperventilation it certainly was much quicker than your typical breath-up and you probably blew off quite a bit of CO2.

Jason

Yes, I definitely remember my not-so-slow breathe up. :duh From what I'm seeing here, this could have contributed to it. The following session I was twitch-free, preceeded by a slow breathe-up. So, in short, blowing off too much CO2 may cause twitching, is that the correct understand of what's being said here?

Good stuff...this forum really comes up big sometimes.

 

[tylerz]

When I had the frantic eye experience, I did a 40 sec firebreathing (rapid shallow hyperventilation) as my static breath-up. Which definately is the fastest reducer of CO2. So, this matches what Jason W. is suggesting. It is a relief to hear that it has happened to somebody else!

However, once again we get to the old hyperventilation concept. I do not understand how hyperventilating (fast reduction of CO2) is going to be any different than a slow breate-up (slow reduction of CO2) when in general you are beginning the static with the same amount of CO2 in your system. The speed should be irrelevant. The initial volume of CO2 at the beginning of a static seems to be what you are guys are suggesting, which has to do with the length of time you put into hyperventilating or slow breathe-up.

I find for myself that a slow 6min breathe-up is the equivalent of a 40sec firebreathing (hyperventilation). I judge this based on when I get my first contractions.

That being said, if we just assume that we are talking about starting the static with less CO2 in our system than normal, irrelevant of how we got there, then does anybody have a suggestion of reason for why a more alkaline state of the body would induce twitching? What does less CO2 in the body have to do with twitching? It may be correct but what physiology does this link to?

Cheers,

Tyler

 

[naiad]

Hyperventilation can even cause blackout, I'm not sure why but I think it has something to do with vasodilation or vasoconstriction. Maybe a milder version of this effect can cause twitching, a bit like samba.

Lucia

 

[tylerz]

The idea of hyperventilating "causing blackout", besides vasoconstriction (which I have to look up), is that your blood cells increase their affinity for oxygen molecules, thereby hindering the transfer of oxygen out of the blood. The consequence is that the brain senses a decrease in oxygen same as when their is low oxygen conditions.

Vasoconstriction affecting blood flow to the brain was addressed at some of the talks at the World Championship, but I will have to listen to what was said again. Didn't understand at the time what was being said.

However, once again it should not be different between a slow and rapid ventilation of CO2 unless the body is responding to a sudden change in oxygen transport. However, you would think that would only be applicable at the beginning of a static then, when the sudden change occurs. That is why we often blackout at the beginning when we pack. The combination of this low CO2 condition and a sudden pressure at the thoracic. Conditions as the static progress or a dive progresses become more favourable for the transport of oxygen, as CO2 increases, pressures decrease, and the body has time to adjust to the circumstances.

So, the cause of blackout should not be "hyperventilating", in the sense of rapid reduction of CO2, any more than it should be caused be slow reduction of CO2, or I would not think significantly, other than giving your body more time to adapt to adverse conditions.

My thoughts... anybody?

 

[JasonWelbourne]

In my experience with the [vertigo, world shaking back and forth] phenomenon which I do not associate with random twitching, It has followed immediately severe hyperventilation. A lot of times I will experience, after doing my breathe-up and begining my hold, a tingling in my brain and a slight darkening of my vision which I associate with blood pressure changes. On this particular occasion I experienced that as well, and it felt like my head started shaking and was going to fall off of my body. I started breathing and everything returned to normal and a feeling of severe inebriation lifted from me over the course of 30 seconds of normal breathing.

Today while doing negative dives, I experienced a similar sensation while making my ascent. I breathed out ro FRV and descended with no effort down a line to prob 12m. During the dive I did several mouthfills and equalized regularly. I probably his reserve volume at about 8m or so. I felt the pressure start to build on my lungs, and after the sensation reached it's peak, I began my ascent.

During the ascent I experienced some *mild* version of the aforementioned phenomenon. My vision got kind of shaky, and I experienced strange contractions unlike any I have ever experienced before. They came in groups of threes and were very quick and intense. I experienced them maybe three * three times on the way to the surface. My total downtime was probably 1:00 but I didn't time it. I was alone, so I have no objective observation to report. I was honestly under strain (hypothermic and exhausted) and probably hyperventilated prior to diving. I initially assumed that I had a lung squeeze but upon surfacing confirmed that I didn't. I have recorded the event in my mind as O2 contractions. Are these symptoms consistant with low O2?

 

[jimbodiver]

Folks -- I have "suffered" from sleep apnea (central, not obstructive), as well as PILMS, or Periodic Involuntary Limb Movement Syndrome, which is the sort of jerking or twitching that some people have (to greater or lesser degrees) when they are falling asleep. These are also sometimes called hypnic jerks (not sure if I spelled it correctly.)

In my case, I also sometimes have these twitches long after I have fallen asleep, which causes me to be aroused from sleep -- just enough to break off the REM cycle. (As a result, I've had several sleep studies over the last 10-15 years, to determine the impact on my sleep, as well as the impact of my sleep apnea on my blood O2 levels, etc.)

Anyway, even though I do have these twitches when falling asleep (and sometimes while fully asleep), I've not noticed them at all during dry or wet static apnea performances....from zero up to my PB of 5:12. My guess is that the twitching mentioned during apnea is similar to the twitches or jerks that happen in the sleep and pre-sleep cycle. Reason being that in both cases the body is relaxing (probably with eyes closed), and the "twitch" is the body's attempt (so say my doctors) to ensure we're not falling asleep at an inappropriate time (such as while driving a car, or while sitting perched up high on a tree limb). Just a guess....

 

[Bill]

This is a normal neurophysiological occurrence that has to do with the mechanisms of falling asleep.

Veronika[/QUOTE]

If you've studied these 'mechanisms', can you tell me if one loses all memory of the last 7-8 seconds before sleep? This happens if you are knocked unconscious or blackout, but I haven't had a chance to ask if it happens under normal conditions. The doctor said it had something to do with the time it took to convert the electrical signals to chemical, to store in memory.
Aloha
Bill

 

[samdive]

falling asleep twitches - we used to call it the "caveman reflex" - some ancient thing to stop you feeling in too deep a sleep when there are predators about! or at least someone told me that... I have also heard them called "cosmic jerks!"

I get twitches during static, always in the same place, in my right ankle. My foot kicks out and once kicked another freediver in the head... rather painfully.

but the twitches are generally a sign that the static isn't going too well. If its a really comfy one they don't happen. The bummer is that they happen quite early and sometimes people think it's a samba

 

[BlueIcarus]

Hello,
I always know if my body is in an overtrained-state If I go to bed and get sudden twitches just
at the transition from awake to sleep. The twitches return me to a full awake state. I don't sleep well,
my heart is not steady and wake up not fully restored. I'm sure that this twitches are there all nigth long..
If I have trained the right way it's the opposite thing: I fall sleep completely relaxed, like I have no limbs and wake up in the morming completely refreshed
By training I mean any kind: apnea, weights, cardio... But have to recognise that most of my overtraining comes from cardio training (or circuit training)

The exact reason of this 'overtraining/not enough rest' is lack of Potasium, but don't know the why's
and when's

Bye!