It sounds reasonable, but the question is whether the additional stress and muscle work won't distract you mentally and physically too much. It may need some serious drilling. I think you are one of the few ones who can test it and tell us whether it helps you pushing further. Perhaps it may be best done in cooperation with an experienced freediving physiologist who can plug you on some devices to see what's going on. I bet that most of the docs working in this area would love to cooperate on such project with you, Dave.
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Dynamic Apnea
- Thread starter frogmansailor
- Start date
Thread Status: Hello
, There was no answer in this thread for more than 90 days.
It can take a long time to get an up-to-date response or contact with relevant users.
It can take a long time to get an up-to-date response or contact with relevant users.
BTW, strangely, in this document (Hemoptysis Provoked by Voluntary Diaphragmatic Contractions in Breath-Hold Divers -- Kiyan et al. 120 (6): 2098 -- Chest), the authors apparently use the term "voluntary diaphragmatic contractions" for the contractions that I definitely do not consider voluntary. Not sure why it is so, but I dared mentioning it to avoid possible misunderstanding when reading some similar documents or discussing with physiologist. I do not know though if it is common to call the contractions so, or whether it is rather a deviation at this specific research team.
OK, this similar article seems to explain the voluntary diaphragmatic contractions better. They tell:
At the first document, I was quite confused, because at least at the second and third cases, it did not sound like voluntary contractions to me - at the second, it was written "he experienced voluntary contractions". Personally, at indeed voluntary contractions, I would not use the verb "experienced", but rather "performed" or similar. And at the third case, they wrote "had diaphragmatic contractions just before the ascent (because of short surface interval)", which also sounds more like the classical contractions to me, than realy voluntary ones.
So unless the authors are inexperienced and completely misunderstood the mechanism of contractions during apnea, it indeed looks like the voluntary contractions are used by some freedivers to push the breath-hold further.
At the first document, I was quite confused, because at least at the second and third cases, it did not sound like voluntary contractions to me - at the second, it was written "he experienced voluntary contractions". Personally, at indeed voluntary contractions, I would not use the verb "experienced", but rather "performed" or similar. And at the third case, they wrote "had diaphragmatic contractions just before the ascent (because of short surface interval)", which also sounds more like the classical contractions to me, than realy voluntary ones.
When I mentally block contractions, Brachycardia is more pronounced. A training partner of mine has been having contractions later and later recently, resulting in longer dives. And before you ask, it's not a comfort thing, I'm talking hypoxia as the limiting factor here.
I'll read the articles when I get a chance, but I have my doubts about contractions increasing pressure in the heart and lungs in a meaningful way and even more doubts about that having a positive effect.
I'll read the articles when I get a chance, but I have my doubts about contractions increasing pressure in the heart and lungs in a meaningful way and even more doubts about that having a positive effect.
Yes, of course, getting the contractions later during the terminal phase of the apnea is certainly better than experiencing them already early in the breath-hold. There is a threshold when the negative aspects of the contractions (mental stress and physical effort, hence higher oxygen consumption) will overweight the positive effect. So when the contractions are too early, they may limit you more than helping.
I would expect that the test subjects were performing the contractions (if they were voluntary...) not to increase the efficiency or potential duration (time to BO) of the breathhold, but as in order to make themselves more comfortable or distract themselves from the discomfort.
I would be interested in testing this sort of thing, but I am somebody who gets early contractions. You need a subject who gets none, so that they can try voluntary contractions to see what difference it makes.
Yes, I guess you are right.
Ah! I though you did not get any - had to confuse you with someone else. AFAIK Mifsud does not get any, but I though one of you the top freedivers and residents on DB is the same case.
He's talking dynamics there, methinks.
Ant Williams experiences few or no contractions. He might be a better bet...
AWW Dave are they picking on you?????
I'm new to Free Diving (did my No Bubbles course instructed by Dave and Fran just last Nov.) but I don't think I expereince any contractions as such.
I can swim just on 90m now (dynamic with fins) 50m without, and don't really expereince any that I remember.
I can also collect Schallops in 17 - 25 metres of water all morning long, feel absolutly stuffed, and like I've dived a little too deep too often, and definatly should have been taking longer surface intervals, (what can I say there's kai to be a gatherin' dowh there!) nope still no contractions.
The fact that I haven't had long to really push myself yet may well be the reason. Or maybe I'm just lucky. Dunno.
Oh yeah 4min 20sec Static. Nope no contractions.
one last PS...
Sorry to whoever this thread was hijacked from...
Last edited:
Not a problem on that hijack, this is quite interesting.
I was just able to push myself to contractions the other day (static - contractions starting @ 2:40) and it managed to push me to 3:09 when my longest before that was just about 2:35. I had never experienced them before. It's quite a unique experience (kind of like a hickup ish type thing?) I can't really think of anything else to describe it, but I think thats what it was.
I was just able to push myself to contractions the other day (static - contractions starting @ 2:40) and it managed to push me to 3:09 when my longest before that was just about 2:35. I had never experienced them before. It's quite a unique experience (kind of like a hickup ish type thing?) I can't really think of anything else to describe it, but I think thats what it was.
You know, it's refreshing to know others don't start having contractions (if at all). My hubby always thinks I am full of "it" when we are doing tables and I have no contractions. He can be sitting next to me, stomach jumping after 2:30, and I'm fine until right before 4:00...and even then, the contractions are SUPER small. In dynamic, I've not yet gotten them (but I've only gone a little over 50m w/fins). With free immersion, no real contractions sometimes...at least not if I've breathed up properly. They may hit when I reach depth, but have never become uncomfortable. I'll refer my husband to this thread so he sees I am not crazy!
That sounds like for You, "breathing up properly" involves quite some hyperventilation! You might want to re-think Your breathe-up routine.
In most of my CW dives ,with or without fins , I get contractions on the way down at about 45-50m ,and their intensity depends of how relaxed I began the dive.
Dave, you said in CWT you get contractions on the turn (100-110m),right?And in DYN you get them at 50m......it's seems that in CWT the dive reflex is stronger and therefore you get contractions later.
Dave, you said in CWT you get contractions on the turn (100-110m),right?And in DYN you get them at 50m......it's seems that in CWT the dive reflex is stronger and therefore you get contractions later.
Actually, I absolutely DO NOT hyperventilate. During formal instruction from Martin Stepanek, I was taught not to do this. Instead, I practice a different "breathe-up" routine. It is taught in the FIT Level II course!
--Billie
I don't believe I've experienced contractions yet. I'm comfortably swimming 75+ yards dynamic without fins. But, I'm a novice and I expect they'll happen sometime. Perhaps when I start trying tables or apnea walking?
