Advantages of FRC diving?

[DivingDane]

Hi All

i have a couple of questions about Exhale/FRC dives, maybe a couple of the more experienced members diving FRC can Answer.

this direction of diving is very interesting as it seems very natural (wales, seals etc do it) what i would like to know is the following:

1. What are the benefits over inhale for constant weight
2. Is there any advantage to doing it for Dynamics
3. long term would it be possible to equal inhale dive depths/ distances using FRC?

i understand that i would be taking a big step back if i was to change to FRC diving but i think the long term benefits would be worth it?

Any comments greatly appreciated.

DD

[cdavis]

I've been working on exhale diving for about a year now, so I'm no expert, but I'll address question 1 from a newbies perspective.

Diving exhale essentially forces you into making the trip down a low or no effort experience. This allows your dive reflex to kick in much stronger than otherwise and before you start producing much c02. The end result is lower c02 levels and higher 02 levels in the core and brain. After you start exercising, a strong reflex keeps the c02 pretty much in the legs. You are safer and much more comfortable so long as you are not pushing deep into anaerobic exercise. My dive times have also gotten a whole lot longer. Now, if I can just get comfortable south of 20 meters, all will be golden. It can take a long time to get used to equalizing at depth when diving exhale.

Good luck with it.

Connor

[trux]

Yes, Connor is right. I'd just like to precise some facts on the metabolism: the production of CO2 in the core will be about the same as normally (working in aerobic metabolism), while extremities (legs, hands) will produce only little of CO2. When the diving response kicks in, namely the vasoconstriction in extremities, the blood circulation will be quite limited to the peripheral parts. It means the muscles will have to switch to anaerobic metabolism, producing acid lactic instead of CO2 and H2O like in aerobic mode. The acid lactic will be reconverted into CO2 and H2O later, once oxygen is available again.

Otherwise, you will find plenty of info about FRC here on DB - just enter the term FRC into the search box above in the menu. You may use the advanced search mode and limit the search to titles only to avoid too many hits Also look up posts by Sebastian Murat. You can also check the links here: FRC @ APNEA.cz Especially the article by Sebastian Näslund is quite informative.

[efattah]

Originally Posted by DivingDane

1. What are the benefits over inhale for constant weight
2. Is there any advantage to doing it for Dynamics
3. long term would it be possible to equal inhale dive depths/ distances using FRC?
DD

After 3 years of FRC diving, I would answer with my opinion as follows:
1. Benefits for CW
- Far greater enjoyment, due to no stressful packing, no stressful final breath, no danger of packing blackout, no complicated water entry and difficult descent technique. No narcosis, no feelings of doom/fear at the bottom, much better feelings in the lungs, feeling more squeezed and bloodshifted like a seal. In general, just a far greater enjoyment of the dive. Also, much shorter recovery between dives when diving in succession. Great enjoyment of the long sinking phase.

2. Dynamics
Laminar and I have recently started doing FRC dynamics in the swimming pool. While FRC does, at first, seem to give no advantage in the pool, it seems I may have been mistaken about that. Quite frankly I have been astounded at how far we have been swimming. How is it possible? Possibly, a far lower drag due to much smaller lungs and smaller chest (i.e. smaller frontal surface area). This allows a much faster speed than with giant lungs from packing. Almost no ballast or neck weight is needed, further reducing drag. Greater hypoxic tolerance due to better blood flow to the brain means you can push way farther without a BO. During packing swims, blood flow to the brain is seriously impeded by the huge pressure on the heart. Ultimately, it appears that the 'limit' for swimming FRC dynamic is only somewhat shorter than with packing, but not dramatically.

3. Distances/Depths: FRC vs. Packing
For dynamic, the ultimate distance seems to be a bit less, though I still find it far more enjoyable than a packing dynamic. For constant weight, the story is far more complicated. After my FRC dives at Vertical Blue 2008, I was able to get a more accurate estimate/calculation of the plausible limit for an FRC constant weight dive. According to my estimate, 120m FRC CW is very possible -- more than that is possible, but you never reach the theoretical max, so I think 120m is practical. The dive would last far shorter than a similar dive with packing. This would also be possible with virtually no CO2/N2 narcosis or O2 toxicity, which is the current limiting factor for packing dives. Although packing divers like Mullins could theoretically do 150m in constant weight if it were not for narcosis/O2/CO2 problems, I predicted many years ago that a wall would be reached around 125m which would be almost impossible to pass with packing. So I would say that once you adapt to FRC diving, and your residual volume shrinks, and equalizing becomes easy, then your depth can be very similar to with packing.

Laminar and I are hoping to challenge the world records in CWNF and CW at Vertical Blue 2009, with FRC dives.

In my case, I took a huge step back in September 2005 when I switched to FRC, and it was hard to watch everyone else get better and better while I started back at square one. However in retrospect, it was the best decision I ever made.

My only warning is that if you switch to FRC dives, always always dive in very controlled conditions with good buddies & safety at the start. The sensations in the lungs and the breathe-up and everything is so different. You need to breathe-up much less than with packing, and you could inadvertently end up hypocapnic and suffer a major accident. It takes about a year to 're-learn' how to judge your body safely once you switch techniques.

Anyway I hope that answers the questions.

[DivingDane]

Eric

Thanks for that, it is exactly what i needed to know and answer the quries i have, so looks like it is definetly worth me heading down the path, i am only new to actual frrediving but have done a couple of shallow FRC dives before and they felt strange but good so i think i will continue.

you mention the prep for an FRC dive is VERY different. In what way does it change (has this been written about before? if so sorry), i currently dont pack on inhale dives as i'm not going deep enough yet (100ft with bifins)

i know this is getting off topic but you mention a feeling of doom at the bottom of a dive, i'm assuming this only occurs in deep dives, or does it occur in all dives where people are approaching their limit, like i said above i'm not a deep diver yet so have not experienced this feeling.

Thanks for all the information guys

DD

[Kars]

Intresting, very intresting !

Great questions and awsers, thanks!

Could an 'intermediate way' not be succesfull?

Taking a modest, easy 80% breath, good duckdive, 5 strokes and than freefalling?
At the WC in Sharm I took just a full breath, without packing, and indeed it was the most comfortable dive of the week.

I think I'll get to taking less air gradually over this year. We have shallow water so taking less air is great for flexability and equalisation practices. I know in guy in Spain and he also got into FRC big time and I'm looking forward training more with him. I hope he will chime into this great discussion.

thanks, Kars

[azapa]

great stuff. As you mention Kars, 80% could be a good way to start. I told Eric at VB2008 that I had never learned to pack properly and he said that I was lucky! The impression I received was that going from pack to FRC is hard (one is used to the "full tank" feeling). I think Eric's dives are about 75% volume, and he has 8l lungs? Please correct if I am wrong.

[efattah]

I'm going down with about 50-58% of lung volume (4.2L); the reason for the 'range' is that my max inhale used to be 8.05L, but now I doubt I can even get 7.40L, so it depends how you do the division (4.2/7.4 = 56%), 4.2/8.05 = 52%.

[Jonta]

Do you recommend FRC to start whit for one whos alomst totaly new to freediving?
Im just 15 years old so i have no plans on packing anytime soon if ever.

[Fondueset]

just climbin' on board

[Jonta]

ok :P
Do you have to learn frenzel to dive FRC? Im mean when diving FRC you dont have as much air to eqalize(forgive my bad enlish) whit. Or can you still vasalva to a certain point as in normal diving(normal=fullbreath no packing)?

[azapa]

i have noticed that those who pack use a lousy "full" inhale, and do the rest with packs. I suppose the math seems better, although from the first pack you are already on breathold.

I remember the worst blackouts (not whiteouts=overpacking) I saw at a competition were from overpacked divers. like, 20 to 30 packs (20 seconds packing) and then fighting the dive to become negative.

[efattah]

I recommend a beginning diver to start on a full inhale or almost full inhale. Then later move to FRC. Frenzel is a must learn technique. Valsalva is very dangerous, it increases the risk of lung squeeze and burns lots of energy.

[Mullins]

Simon - not too sure about either of those things. Re the second one: the apparent correlation between packing and deep BOs may simply be because the divers who are packing lots are the same ones who are pushing hard. The two go together quite well. I expect if they'd done the same depths without packing the results would have been just as bad or worse. There is a buoyancy-change penalty associated with packing, but not enough to outweigh the benefits for most divers (possibly not all) if we're talking pure performance potential.

Also, as a packing diver I've found it fairly easy to transition to shallow/medium FRC dives, though I haven't tried deep ones. I still suspect packing helps increase the overall flexibility of your chest, inwards as well as outwards. I haven't seen evidence either way, just my observations which are limited

Originally Posted by DivingDane

Eric... i know this is getting off topic but you mention a feeling of doom at the bottom of a dive, i'm assuming this only occurs in deep dives, or does it occur in all dives where people are approaching their limitDD

Narcosis. Not pleasant!

[watts]

Eric in vb2008 you said you used 1 litre over FRC why is this? Just for equalizing or breathhold. How are you finding consistancy with this as i find frc realy quite acurate but anything more seems a bit off (checked with spirometer). You are exhaling down to this right not inhaling up. You also used a neck weight and had the weight of the mono too this would have to be a few kgs.

Thanks Nat

PS 67 frc you da man