The Bloodshift feeling

[par2005]

Hi every1,

I was sitting and wondering about so called "bloodshift". Could anyone try to describe

What is the feeling when you experience it? Is it painful? Relaxed?

At what depth do you encounter it?

Is the depth ~same for all of us?

Thanks.

 

[penguinator]

It may be different for other people, but I really cannot feel a thing rofl

Im guessing sometimes you might feel a tingling in your extremities?

 

[jimqpublic]

Which bloodshift are you referring to? Presuming that you mean the shunt from extremities to the core I don't think it requires depth as much as simply immersion in the cool water. You can detect it by a full bladder. The blood shifts to your core, causing the kidneys to sense increased blood volume. In turn the kidneys remove water, reducing the volume and concentrating the hemoglobin. I find it happens quickly after getting in the water. At least I generally have to urinate within 1/2 hour of getting in the water even if I went just before.

The spleen also contracts which puts even more hemoglobin into circulation. From things I've read here on Deeperblue this happens from hypoxia. In one of the discussions of Statics it was suggested that a 2 minute hold will trigger the splenic contraction.

Finally "thoracic filling" is when you go quite deep and your lungs begin to fill in with extra fluid. That requires much deeper than I'm capable of. Something like 40+ meters.

I've been trying to accelerate the dive response by doing a few quick dives; one or two shallow mostly-empty-lung (passive exhale) dives; then a couple minutes of facial immersion (mask off, snorkel in); and then a a static hold floating on the surface. It seems to be helping- previously my initial dives were all about 30 seconds taking a full hour in the water before they crept up to approach a minute. Now, doing the four things listed above takes about 10 minutes and my dives are much easier- though still 1:00 seems to be the point that I want to ascend.

This is sightseeing freediving or spearfishing in 5 to 10 meters of water. Without the warmup listed above I find it's really hard to get in the "zone" in shallow water.

 

[azapa]

like JIMQ says, the biggest thing I "feel", or rather notice, is that initial cold feeling in the extremities (forehead, hands, feet) disappears in a few minutes as blood flowing to these regions is diminished, other than that, I don't notice much. Another noticeable thing, although not 100% a blood shift issue, is how bellow 15M the pressure helps the comfort factor or gives what is know as the "feeling of well being". Safe dives.

 

[par2005]

The question was more related to the bloodshift down there, below 40m, when the blood plazma fills/surounds lungs

 

[Sergiu]

Indeed, i am also very interested to hear the feedback from the deep freedivers who go regularely below 50-70m where bloodshift has happened. Anybody hearing our call?

 

[jimqpublic]

It's definitely not a "beginner freediving" issue. Try posting in the "general freediving" forum.

 

[Mullins]

No particular feeling for me, though if I am doing a no-warmup dive I can feel my legs getting 'tight' and starting to ache slightly even before I start kicking off the bottom. A feeling of pressure on my chest builds until about 50m but doesn't change from that point on. If anything it lessens slightly past 70m or so.

 

[demasoni]

I agree with the tightness in the legs, in particular my thighs. During the descent glide, it feels like pressure cuffs are bound around my legs squeezing them until they kind of hurt/itch - if that makes any sense...

I get this feeling the most when my breath up is made up of relaxed, small, normal breaths - no purges, ventilations, or packing.

 

[EARL1220i]

hi guys im from the phil. i would like to ask something i have been diving for almost 5 years now every weekend if i hve time. its about my lung left lung to be exact it has fluids in it and i have it remove last year ive undergo thoracentisis removal of fluids to my left lung. the doctors says i have no problems in my lungs. is it posible that i got it in freediving? last two years ago i have bends after freediving 80 ft. i would like to know if a freediver can get plural fluids in lungs? i dont want to stop freediving i can still go 80 ft now and can hold breath to 3min. i need to go again in thoracentesis cause i have fluid again in my lungs. the doctors says that they dont know the cause of it. can you guys help me.