Exhale (FRC) Adaptation

[The Exhale Diver]

Very interesting Eric, I hope your competative dives go well.

I too am interested in the equalising, is it possible to perform a second mouthfill?

Any ideas why you have experienced an iron deficiency?

 

[efattah]

A mouthfill at 14m can get me to 85m, because I can reach 4 times the pressure of my mouthfill depth... i.e. on a mouthfill at the surface on a full exhale I can reach 30.5m (4.05atm) from 1 atm at the surface; this is with a sphera mask; it is more with goggles.

If I pre-fill my sinus cavities with a sort of gel, then my sinus deadspace is reduced, allowing my mouthfill at 14m to get me to 100m+, but I haven't proven that theory yet.

In terms of iron deficiency, I only eat red meat about once a week. The amount of iron needed to produce lots of hemoglobin and myoglobin is far beyond the iron store of any normal person. I would say that 95% of people would become severely iron deficient upon assuming a strongly hypoxic training program, especially the FRC type. In my opinion, if you are training hypoxically routinely, and you have reached a plateau, it is because you are iron deficient.

When training for Monaco I had a little bit of 'stored' iron from not training for a while. I started training and experienced rapid improvement in the first 7-9 days, followed by a plateau for the remaining 6 weeks (including the appearance of dry cracked skin on my hands). All those 6 weeks of training were worthless and useless, because without iron your body cannot adapt to the stress of training.

Other symptoms of low iron include moderate depression, general fatigue or weakness, reduced sexual functioning, weakened immunity, and feeling unusually cold during the day.

 

[Absolute]

Hello,

Lately I have become interested in diving on FRC after reading so much about it on DB.

So I tried it out the other day in the back channel that rarely gets used at the marina. 3m deep, many meters long, 60m wide, sea water. Reasonable vilibility, no current, no boat traffic.

It feels great to be able to sink to the bottom right off the bat. The first day I was only in the speedo and started to get a little cold twards the end of the hour. On my last static I was at 2min, still feeling good, but shivering. I was happy enough with the days training that I surfaced and hit the showers.

The second day was a success as well. Feeling very comfortable at the bottom, doing statics and dynamics combined I was amazed at how efficent I was moving through the water. I don't think that I have ever been that fast underwater in my life. It was like a 3 knot current was behind me.

So yesterday the third day in a row, I marked out a 126 ft (38.4m) line stretched this line out on the bottom to serves as a reference to distance and also keep me going in a straight line on the bottom. (Problem I found on the second day) This time I wore the 3mil suit, pants and top with hood, no more sinking, even with totally empty lungs! So I ended up wearing 2kilos and was able to get to the bottom easy enough and stay there with one arm stroke. This is the same weight I would have to use on full lung dives and would not be neutral until 10m with only pants and rash guard.

I was once again suprized at how fast my heart rate really slowed down on exhale dives. Granted I would get a heart rate decrease on full lung dive but not this fast.

So yesterday went like this.
5min rest
57 static (easy)
3 min rest
1.21 static
5min rest
1.44 static
5min rest
35sec static 40sec dyn 80ft (24.3m)
5min rest
45sec static 50sec dyn 126ft (38.4m)

Still feeling good and ready to go again, but it was starting to get dark, my dog was getting rained on, and I forgot to take the chicken out of the freezer, (oops) I decided to call it a day.


I plan on training further and doing some depth (will be happy for 20m) on Monday or Tuesday. Squeeze time.

 

[naiad]

Hi Jay, I hope there is a buddy supervising you when you are training.

Your distance is good!

Lucia

 

[DeepThought]

I plan on training further and doing some depth (will be happy for 20m) on Monday or Tuesday. Squeeze time.

Yeah, I'm also hoping that you are experimenting with a buddy (besides your dog, how well traied it might be).
Besides that I'd like to encourage you to take the depth issuse slow... I don't know how well you are trained to do depths so this is a general warning. Try to spread your depth progress over a few days or even weeks... It would be sad if you'll get a lung squeeze from progressing too fast, you'll definitely lose more than you'll gain...

 

[Absolute]

Thank you Lucia, you are so nice.

Michael thank for the heads up on the lung squeeze. I will start off shallow and safe at first and see how it goes.

I had a good time yesterday. 4 FRC statics last one ended 2.27 @ 3m Then started on static/dyn.
1m sta 44s dyn 124' (37m) After surfacing I had a hypoxic buzz in my finger tips little in my arms and legs but not in my head .
After 5m rest I did 1m sta 51 s dyn 136' (41.4m) Felt good after surfacing just stiff legs .
Last one was 1m sta 40s dyn 100' (30m) Did not feel good on this one so pulled up early and got out.

Once I got out I got the hiccups! I haven't had the hiccups in forever. Don't know what caused that but I took me along time to get rid of them.

Don't worry I use a spotter.

 

[Oligo]

Very interesting thread, but I do have one question. Stress initiates the Fight or Flight response that is usually defined like this: "Fight or Flight is a physiological/psychological response to a threat. During this automatic, involuntary response, an area of the brain stem will release increased quantity of norepinephrine which in turn causes the adrenal glands to release more adrenaline. This increase in adrenaline causes faster heart rate, pulse rate, respiration rate. There is also shunting of the blood to more vital areas and release of blood sugar and other chemicals, all of which is involved in getting the body ready for fighting the danger (a tiger, a mugger), or running away from the threat. Feelings of dread, fear, impending doom, are common."

So it is well known that stress channels blood away from limbs, but what about the heart rate? Doesn't increased heart rate increase consumption of oxygen? All my experiences with stress combined with freediving have lead to diminished performance (for example competition stress).

The way I see it, stress would make your surface HR very high. Thus when it drops due to DR, the drop would be high. But if there was no stress, then the surface HR would be low already, so DR would not be observed to cause HR drop as much.

Or should I get stressed only AFTER hitting the water and starting apnea?

 

[efattah]

Norepinephrine alone doesn't increase your heart rate; it is the interaction with some other receptor (alpha-2?), which may not always occur.

Initially, stress used to decrease my diving ability (fear during competitions etc.)

However, as time went on, I found that the stress of the competition would INCREASE my diving/static/dynamic ability. I definitely felt that the blood shift was stronger during times of stress. In my case, heart rate doesn't seem to affect the length of my swims/statics/dives, so I'm not sure what my heart was doing.

 

[Oligo]

That's quite interesting. I wore a pulse monitor (that I could not see during the performance) to a competition and it showed that my HR was way higher than normal before the start of the dive and it barely dipped at all during the dive. Needless to say, i did not do very well.

Seems to me different people have different reactions in this area. So maybe "stress diving" does not work for everybody?

 

[naiad]

Once I got out I got the hiccups! I haven't had the hiccups in forever. Don't know what caused that but I took me along time to get rid of them.

They say that to get rid of hiccups you should hold your breath, but if that's already what you have been doing...

In my case, heart rate doesn't seem to affect the length of my swims/statics/dives, so I'm not sure what my heart was doing.

Same with me - sometimes, both in the pool and dry, I have had an unusually high heart rate during static apnea, and it doesn't seem to have any positive or negative effect.

 

[DeepThought]

Once I got out I got the hiccups! I haven't had the hiccups in forever. Don't know what caused that but I took me along time to get rid of them.

Only since I discovered freediving I found a way to get rid of hiccups. It's so simple it's surprising. What I do is parcticing calm full conscious breaths, in slow ryhtem. Since I'm breathing consciously I don't hiccup and after a few breaths I feel the urge disapeared.

Just found out I wasn't the first to find that out, here's some more info: [ame]http://en.wikipedia.org/wiki/Hiccups[/ame]

 

[jome]

I just hold my breath until the hiccups stop or I pass out. Never passed out so far

 

[Absolute]

I had to stand in the shower and totally relax my diaphram, (make my belly big) watch it for a while and breathe slowly through my nose. This did it the first time . When they came back later in the evening, drinking a glass of water slowly was enough to do the trick.

Went spearing and got a chance to test out my FRC dives.
My bottom times were not what they used to be but still managed to get 20 to 40 sec on 12 to 15 m dives. I think that I would have done better if I did not have the gun with me, hard to relax, but gliding down to the bottom with no weight is something I really enjoy.

I'll see how it goes today. Were taking the boat to small island south of here. Cocos island. More diving and fishing..

 

[Ben Gowland]

Hi Guys (& gals),

I thought I'd add in some info & experiences from my recent trip to Greece where I got to do a great deal of FRC diving. I've been diving in this way for several years now, although it must be stressed that I do not dive frequently, nor deep. The best I get is about once or twice a week in the summer to a max depth of 20m.

Fi and i went to Greece for a fortnight and so got the chance to dive once or twice a day for a god solid 12 days. I went out in my usual steady state of health with a normal reasting heart rate of about 46-52 (and my 'extra' stone of weight). More on this later.

Within a day or so I was diving in my usual recreational FRV style up to 30m in my Cressi Superocchio mask and 5:3 suit. I tend to do 1 arm pull and 2-4 kicks then sink. Dive times were about 1-1:10 to start with. After a week my dive times were up to 1:10-2:00.

After the first week and some empty lung tests I realised that my usual FRV diving breath was not quite a 'proper' FRV. It was slighty more. I've suspected this for a while but knew that it wasn't really that relevant when only diving to 10m. My neutal bouyancy was about 10m with full lungs, about 5-6m with my 'normal' FRV ad about 4.5 with a 'true' FRV. [This is mainly because the 'spare air' effects of partial lung collapse should only happen some way past RV, which isn't going to happen on a 10m dive. Equally, the usefulness (O2 content) of that 'spare air' is maximised by diving with the smallest lung volume possible. The longer it takes before lung collapse, the more O2 will be lost to the blood and also the earlier in ascent the spare air will return to the lungs - theoretically you want it right at the end of the dive (last 10m or so)]

Anyway, I digress. So, I started trying to do deep dives on true FRV. The first time I tried I got to an equalising limit at 25m and was rather dissapointed (mouthfill at 15m). However, on the next dive (5 mins later), I was down to 35 without problems (mouthfill at 20m). I think this was probably due to the blood shift incurred after the first dive. I spent the next 2 days doing lots of dives to my equalisation limit. I got to a new FRV pb of 43m with my normal mask on. The dives were relatively easy with minor leg burn (not far to swim/desaturate myoglobin) and short (1:15ish). I was a happy camper, although I certainly wasn't able to get any deeper without switching to maskless diving. Or do some Fattah-mega-mouthfills! Eric - I'm amazed that you can get to 30m on a mouthfill - I can only normally get to 10!

So, the next time we get to go away somewhere nice and warm (fingers crossed), I'll be better prepared for both deep and recreational FRV diving. I did a few dives on full lungs whilst there and didn't like it particularly - nor did I notice any great improvement in dive time.

Back to the resting heart rate. At the end of the holiday it was down to 40, but sadly I didn't lose a stone in weight (I did get rid of a bit though ). This implies an improvent in my blood/cariodvascular system. I wenty for a bike ride when I got back home and got a suprise. I rode faster than I could before I went on holiday, my legs felt suprisingly easy and my heart rate was very low - but my breathing was terrible. I felt like my lungs were highly inflexible almost to the extent that I couldn't keep my respiration up.

The diagnosis that I made from this situation was that I must have had some kind of adaptation from the diving - possibly increased RBC production and tougened alveoli. It's just a shame that I couldn't test this theory.

Unsuprisingly, now that I've been back 6 weeks and dived merely once, my weight is back to normal, as is my resting heart rate although I have maintained the fitness level that I came back with (only because I have been cycling frequently).

So there you go. I thought this might draw parallels with other people's experiences, or give some hope to those who think that equalisation is a limiting factor in using this method for recreational diving.

Sleep well,

Ben

 

[ISeeTheStars]

Safety?

Dear fellow freedivers,
very interesting thread indeed. After my favourite and inspirational big thread about no breathup no warmup way, I read this and was amazed.
And also it explains a lot to me. I was doing some experiments lately - mostly for fun - with walking on the floor of 4 m deep pool (on exhale). Its a very calm and calming excersise .. but i was surprised to be able to walk almost 20m in this slow pace, on exhale, spending down there longet time then during my dynamics. (Currently 75m assisted, 50m no fins - a beginer )
I started to really enjoy exhale dives, because i experience whats been writen here before ... very fast DR response and very clean head all the way through. I am strongly thinking of starting to experiment more with FRC dives ..
And here comes my concern. Everybody around me is sayng .. dont do exhale dives ... its too dangerous ... you will BO without warning and so on.
Are there any safety precautions that I should know and follow, that are different from those for full lung dives? I am mostly concerned about diferences caused by the amount of air (more than FRC/FRC/Exhale) and if its necesary to first spend that static phase to the extent of (contraction?)

Also there comes another but maybe connected question ... how big is a risk of inducing BO by packing? A few times during descent when i started with adding some packing to help the ribcage i felt really dizzy .....

Thank you and keep the interesting news coming
Pavel

 

[tylerz]

I think it would be interesting to compare various persons' FRC volumes. I performed some spirometer tests the other night and was surprised by the results. Even though spirometers will have variations in accuracy, comparing your FRC to your inhale volume should be interesting too.

FRC volume = 3L
Inhale volume = 7.3L
Packing Inhale volume = 8.3L

Eric what is your real FRC volume?

 

[tylerz]

Or do some Fattah-mega-mouthfills! Eric - I'm amazed that you can get to 30m on a mouthfill - I can only normally get to 10!

No worries Ben, I think Eric has a structural advantage in his jaw/facial layout. I tried and tried and tried to extend my mouthfill from it's mere volumes (1/3 or less of Eric's if I recall) and I never succeeded in budging it even 30mL more. I contorted my mouth, face, cheeks, jaw, and anything else that moved and always came to the same volume.

In the end I could dive to 17m on a mouthfill from the surface and empty lungs. 250mL was the volume I measured of my mouthfill, although consistent on the spirometer I use, it may not be accurate.

Although the total volume contained in a mouthfill is important, some other factors in determining end depth achievable, with that mouthfill are:
- total airspace requiring equalization (mask, sinuses, oral cavity, middle ear volume, nasal cavity, etc...)
- % of oral cavity air that can be forcefully removed (I think this is remarkably different amonst individuals as well)
- eardrum flexibility
- % mask compression before equalization is required

 

[laminar]

Are you all using Sphera's for these calculations?

Pete

 

[tylerz]

Nope, used a Sporasub Samurai.

 

[cebaztian]

volumes

FRC volume = 3L
Inhale volume = 7.3L
Packing Inhale volume = 8.3L
Eric what is your real FRC volume?

Real or unreal FRC?

I assume you are talking WET FRC (exhale done with chest under water).

Here are som results from a Murat course:

subject/VC/relaxedVC (down to FRC)
1 - 4.8 - 3.7
2 - 5 - 3
3 - 7 - 4
4 - 7.5 - 3.5
5 - 7.2 - 5
6 - 6.2 - 4.6
7 - 6.2 - 4.6
8 - 6.4 - 3.6
9 - 6.1 - 3.6
10 - 5.2 - 3.5
11 - 7.2 - 3.9
12 - 6.5 - 3.9
13 - 6 - 3.8
14 - 8 - 4.6

Sebastian

http://www.fridykning.se/freediving/features/muratarticle1.html