Halfway point of breath hold no contractions

[DiveHacker]

If you are using the initial urge to breath as a sort of reference point, is there a length of time after that urge that is considered safe? Double from that time for example?

Most Freedivers seem to use contractions as reference, but I don’t get contractions. It seems the second closest thing I could use as reference would be when I get an urge to breath?

 

[Peter123]

No. Dive save with a freedivingbody who is spotting you during the dive.

A lot of top freedivers say in interviews that at what time in the dive contraction start doesn't realy matters.
For me the urge to breath is the beginning of feeling more and more uncomfortable which will ends the dive.
The only way yo delay the urge to breath is more breathing before the dive but I know this will lead to black out so I don't do it! Easy as that.

 

[Bill McIntyre]

I've never had a contraction.

 

[7BDiver]

I've never had a contraction.

Bill, have you found any reason for not having contractions or have any suspicions? Do you think it has anything to do with an autonomic dysfunction or a dysregulation of the peripheral and central chemoreflexes?

 

[Bill McIntyre]

I have no idea why I’ve never had one, but I always feel left out when people discuss them.

 

[7BDiver]

It would be interesting to see what the difference in dive response is for those that don't get contractions. I have failed to find any studies related, closest being about Chagas' heart disease or Multiple-System Atrophy but they don't quite compare. If there is some sort of Baroreflex impairment it might show in the form of a delay in blood pressure change, no heart rate increase at beginning of apnea or delay in vasoconstriction. Perhaps understanding the mechanism would help estimate safe diving times as the body just changes how it manages apnea. Its a very curious subject.

 

[erixsparhawk]

@Bill McIntyre - I do get contractions but I too am interested in the those that don't. Mostly I've seen it in people with very short beathholds (<2min), however, I have met two with very long breath holds that don't get contractions. How long is your breath hold?
Have you done much empty lung breath holds?
My full lung breath holds have very mild contractions, my empty lung contractions are super strong. I've wondered if perhaps people get them but they are just really tiny and they don't notice them.
@7BDiver Those are some real zebra diseases. I would expect a more simple explanation like a diabetic polyneuropathy. Think long standing type 2 diabetes. Some people get visceral autonomic dysfunction.

 

[don.mario]

hello, I'm yet another non-contraction case. static apnea reaching 6 minutes. empty/ full lungs dives, doesn't matter - never experienced one. healthy as far as I'm aware. and, also, curious, why. please share your thoughts.

ps. I guess this is my 1st post here so hello everyone!

 

[J Campbell]

So, Bill, what makes you stop your breath hold? I'm guessing you get an urge to breathe that builds up stronger and stronger, correct?
I only get mild contractions toward the end of a very long breath hold, but they don't bother me as described by others. What I do get is just a very strong urge to breathe.

 

[Bill McIntyre]

Yes. I just get a strong urge to breathe. But I'm very conservative- I don't let it get too strong.

Maybe I should confess that I probably don't belong in this conversation. I'm not really a freediver- I'm just an 83 year old has been spear fisherman trying to get one more season. I've never done any line diving. I've never done any tables or fancy breathing exercises- empty lung full lung etc. In the kelp beds of California with poor vis its very difficult to follow the buddy system so I seldom have anyone watching me unless I have a fish wrapped up in the kelp on the bottom. Then we try to get our buddies to come back us up but they usually can't see us from the surface. So I really don't try very hard to extend breath hold. Maybe if I were in a controlled situation line diving where the entire point of the diver was maximizing breath hold then I'd finally feel a contraction, but I still doubt it. I've been diving since about 1952. When I was a teenager no one had heard of shallow water blackout and I thought it was perfectly normal to be dizzy and see stars when I surfaced. Its a miracle that I survived, but if I could feel contractions, I think I would have then. But OTOH, maybe I did but just don't remember. Anyway, I'm quite sure I haven't felt any in the last 20 years since I've known that I shouldn't see stars when I surface.

 

[DiveHacker]

I grew up in the water, right near Bill amazing, surfing daily. I sometimes wonder if my no contractions were from being in the water constantly at a young age, not freediving but surfing. I saw that reason posted a few months back and it interested me.

Bill sounds like another data point. Did you start your ocean time at a very young age Bill?

 

[Bill McIntyre]

I’m on California now but I was born and raised in St Petersburg, Florida. My father was a fishing guide and I think I was about 12 when I started swimming around the docks with a Hawaiian sling that my uncle made for me. By 13 or 14 I was using a Champion Arbalete to shoot fish including big Goliath grouper. When I was 15 caught a big tarpon (on rod and reel) and won a big contest and got my picture in the third issue ever of Sports Illustrated. The first prize was a new Chevrolet but I wasn’t old enough to drive so they gave me cash. My father took it all for college except that he gave me have enough for my first tank and regular in 1954. So I was primarily a bubble blower until age until age 57 when I returned to freediving.

I’m not sure how my story proves much about contractions but I have been in water from an early age.