DNF technique / rules

[wjohnson100]

How big a breath you take related to your performance is always a balance between comfort, volume, and induced tension. Basically, take the biggest breath you can comfortably hold that will not induce unnecessary tension. It is entirely possible that someone training exclusively in FRC would do better DYN using FRC than full lung simply because they are uncomfortable with a full breath. There was a guy posting on deeperblue recently who was an FRC diver who was trying to do full breath work and had great difficulty doing it. The difficulty lasted quite awhile too.

FRC has some technical advantages in the ocean, particularly in regard to weighting and work required to go up and down, but these benefits are not available in the pool. Some people actually like the momentum benefits of more weighting in the pool, so FRC would be at a disadvantage here. Thus there is probably no particular technical benefit to FRC in the pool relative to a fuller breath, as long as the fuller breath is comfortable and not inducing unnecessary tension.

One thing I would advise is that even if you are an FRC diver, do some full lung work too, as you don't want to handicap yourself by not being able to take a full breath comfortably when you need it.

These are my ideas, and I am pretty sure that others with more FRC knowledge can add to this discussion if I have made any factual errors.

 

[wjohnson100]

You can tell I am not the biggest FRC fan for sure. I figure when Molchanov(a), Mullins, or someone else at the elite level does a 300 meter FRC DYN, I will believe in it. Till then, I am sticking with full (or close to it) lung apnea. Far as FRC statics go, forget it. If anyone is doing 7:30 or better FRC statics, it's news to me.

 

[EddieP]

Why no weights?

Pool won't allow it. Its not a club session, but I'm doing it in a normal swimming session.

 

[Mullins]

Exhale may be the only option then - but do be careful with it. In particular, avoid overbreathing at all before you dive. There is a lot of information about "FRC" diving on here which is worth reading.

 

[tcrusson]

Exhale for a beginner? Seriously? How fun. I'm glad I didn't start this way, I would have given up fairly quickly ;-)

 

[Phil C]

Hi Guys, Just to set the record straight:

My PB DNF exhale is 6m further than my current inhale PB, It's possible that I could go further on an inhale but not last time I tried (about a year ago). Both my previous inhale dive PB and the recent exhale dive PB I had nothing left in the tank.

I don't train exhale exclusively, just around 50% of pool sessions. I use lots of packing when I train inhale dyn/dnf. I've seen no evidence of exhale diving affecting my inhale volume.

Dave: I think the main reason that exhale dives work well for me is that I get a really strong dive response on exhale which appears to compensate for the less oxygen I have on board. Everyone is different and I think that some freedivers, perhaps to do with age? or just not as 'chilled' get a weaker response than others on inhale .
To illustrate this:

max attempt dynamic to the point of BO on inhale and I get no lactic burn,

Sub maximal exhale dynamic and I get muscle failure so I can hardly walk afterward.

Trux: Have to agree with Dave on the advice for new divers. PARTICULARILY if it's being done away from a structured session. My advice, for what it's worth, is to spend time away from the structured session training a better breastroke kick and dolphin kick.

Here's a drill I do in a local 25m pool, it's got a little CO2 training and a lot of technique training and *should* be safe and ok with the pool staff.

0. Using the pool 60 sec lap time clock (most pools should have one of these) start at '00'.
1. Kick off, streamline arms above head, max 10 dolphin kicks, no further than midway.
2. Breaststroke on surface to end of pool.
3. On back, arms above head, breastroke kick return 25m, work on getting it down to about 10 kicks.
4. Repeat starting at '15' (50m in 75sec including time for 2-3 slow breaths at the turnaround, although breastroke on back is the main recovery)
5. Repeat starting at 30' ,45', 00', 15'....do in 400m sets (twice around the clock) with a short break in between. Try for three sets in a session. If too hard go around the clock in 20' jumps instead of 15', too easy and try 10'.

Concentrate on developing a good undulation in the dolphin kick and a good scull in the breastroke kick.

Cheers

Phil C
Auckland Freediving Club

 

[trux]

Trux: Have to agree with Dave on the advice for new divers. PARTICULARILY if it's being done away from a structured session.

Well, yes, the safety was my primary concern too, and I wrote it in my initial post clearly. And it is clear a beginner (and out of a structured session) is always a bigger concern anyway. But I don't think that in general FRC divers are more prone to BO than full inhale divers.

 

[Simos]

I can't really comment on whether FRC divers are more prone to BO or not (although my understanding so far was that this was generally accepted to be the case so I'm (pleasantly) surprised it's being debated) but I do see 1-2 complete beginners almost every week at training (I always train in the same lane as them and help out as much as I can) and I'd say that FRC would not be appropriate for your average beginner.

If not anything else, most beginners would struggle with FRC and find it stressful and I wouldn't be surprised if some even took water in when getting the urge to breathe, which wouldn't be the most pleasant experience.

Having said this, I do often advice complete beginners to 'take a bit less air in' (not FRC but maybe around 80% of full inhale or thereabouts) - mainly for two reasons:

1. They are obsessing with getting as much air in as possible, resulting in loss of relaxation. Occasionally you get the odd complete beginner that even tries to pack or do something similar to get more air in on the first session (downside of youtube).

2. They are way too buoyant and especially when combined with DNF, some find it impossible to stay down and end up swimming on the surface, which can end up being really frustrating for them.

So overall I wouldn't say that beginners should be taught proper FRC but getting them not to obsess with stuffing as much air in as possible I think is important.

 

[trux]

FRC divers are normally rather less prone to BO for two basic reasons:

1) FRC divers usually do not hyperventilate, they rather dive on high CO2. High level of CO2 increases the hypoxic tolerance, hence you can get more hypoxic without blacking out, while in the same time it makes the urge to breath stronger (increasing so the safety margin).

2) The purpose of FRC is to start the Diving Response as soon and as strong as possible. This leads to an early anaerobic mode of the working muscle groups, and consequently to their failure before the core (heart / brain) get really hypoxic. Hence, you are typically forced to stop the dive before your brain even gets any close to hypoxia.

Now, of course, if you know nothing about FRC and do it wrong, or if you push over any reasonable limits, you can always black out, but that's valid for inhale diving too.

The basic safety concern of FRC diving (if properly done) is not really increased BO risk, but the increased risk of inhaling water.

As for beginners - I have plenty of them in our club all the time too, and frankly told I see often rather the opposite case - they are not able to take a proper full breath. That's why they are usually taught the diaphragmatic and thoracic breathing rather early, to be able taking a real inhale, and not just the typical beginner inhale where they fill their ribcage, while raising the diaphragm, considerably so limiting the lung volume. So many of them dive on a submax volume anyway until they are taught how to do it properly.

 

[Simos]

As for beginners - I have plenty of them in our club all the time too, and frankly told I see often rather the opposite case - they are not able to take a proper full breath.

This is very true. But still I don't really see any very good reason on why someone should learn to dive on FRC from the very start - even if it's a good idea for the pool, it's confusing when you then get to open water to tell them that they now need to be on full lung. Also I think that static would be quite hard on FRC for a beginner.

In any case, back to the original problem of not being able to stay submerged in DNF with full lung - while you can't obviously glide much if you are buoyant, I've yet to meet anyone that has good technique and genuinely can't stay submerged on full lung so I think that resorting to FRC too early to battle this issue is probably masking other issues. Having said that, I think I picked up bad habits in DNF because I dive so buoyant all the time so perhaps it would have been better if I tried on FRC earlier...

I see a lot of people having this problem (i.e floating to the surface) when they do DNF when they first start but from what I've seen it's usually either a head position/posture problem or the fact that their technique is not good enough to get enough propulsion, especially from their kick. Sometimes, you even get the legs working against the arms.

Anyway I'll shut up now as I'm by no means a DNF expert, nor an FRC one - thought I'd just comment on the point about beginners as I can relate more to that but would be interesting to hear if you've had any luck with beginners and FRC Ivo. :martial

 

[Mullins]

I've yet to meet anyone that has good technique and genuinely can't stay submerged on full lung

Hello Simos. My name is Dave and I can't stay submerged with full lungs :wave

I also enjoy long walks on the beach, except when it's covered in oil leaking from a bloody great cargo ship that has been run aground on a well charted, well known and clearly visible patch of reef at full speed by an idiot captain with outdated charts.

http://www.stuff.co.nz/environment/5763630/Mayday-call-from-stricken-ship-Rena

 

[Simos]

Hello Simos. My name is Dave and I can't stay submerged with full lungs :wave

I also enjoy long walks on the beach, except when it's covered in oil leaking from a bloody great cargo ship that has been run aground on a well charted, well known and clearly visible patch of reef at full speed by an idiot captain with outdated charts.

Rena oil spill now 'worst maritime environmental... | Stuff.co.nz

Hahaha I had a feeling that was coming Dave.

Maybe I should have put a disclaimer on the upper size of lung volume lol or have added 'apart from Dave' to that sentence.

Let's just rephrase to that I've seen complete beginners float to the surface very often on the first few sessions (even with fins on) and they are doing underwater lengths fine afterwards without weights or FRC.

Also the reason I mentioned that one can pick some 'bad habits' when training DNF with no weight and full lung is that apart of the non-horizontal angle that means that you need to constantly 'swim' to stay down (very little glide), the kick has to be modified a bit to stay down eg in my case when my right leg kicks it also gives me a downward force (instead of just forward) keeping me down which obviously is not ideal if you have a neck weight on.

Anyway nice to meet you Dave ;-)

 

[Simos]

For the benefit of Eddie who posted this in the beginner section and is new to DB I should clarify that I am the current world record holder in both DNF and DYN and Mullins who's just introduced himself is probably some random guy that has spent a couple of years freediving that spends a lot of time on these forums and is clearly having the same problem as you (and enjoys walking on the beach).

Just so that you know.

(I'm off to edit Wikipedia now and my work here is done)

Ps Dave I actually just noticed the link, won't load on my phone but sounds bad :-( hopefully damage can be limited and everything restored.

 

[Phil C]

I'm sorry guys, just not understanding something here. Why are you guys training people without getting their buoyancy right?

Surely, if you teach people to do DYN/DNF with positive buoyancy they will learn a stroke that is inefficient?

At the AFC the first thing we do is a buoyancy check, get them neutral pitch and overall with mostly neckweights.

However, should any captains of stranded container vessels, or the b###s who decided that it wasn't economic to have an appropriate spill response vessel/gear available to get the fuel oil off a vessel sooner than 5 days after stranding we will be sending down to Wellington for Dave's neckweight (reputed to be rather heavy) and getting them to do some loooong statics on the bottom of the pool.

Phil C

 

[Siku]

Mullins; Hello Simos. My name is Dave and I can't stay submerged with full lungs :wave

So it's not just me that has bad technique, phew!

I'm (a beginner) diving on a range of inhales from frc through to 80% right up to full (no packing, no weights, no wetsuit). I can inhale, and am just experimenting really.


I'm quite happy controlling bouyancy with inhales but is there a problem with varying the inhale in this way? I wonder if I should make a firm decision and train full or FRC... Time to invest in a neckweight perhaps.

 

[Simos]

I'm sorry guys, just not understanding something here. Why are you guys training people without getting their buoyancy right?

Surely, if you teach people to do DYN/DNF with positive buoyancy they will learn a stroke that is inefficient?

You are making a good point - I can't speak on behalf of our club as I am not an instructor. But a few personal thoughts/clarifications on this Phil:

- People can (and do) bring their equipment of course and choose whether to train with neck weights etc

- Complete beginners don't want to invest in equipment from the start usually. There is club equipment they can try but obviously after some point it's up to the individual to sort out their equipment

- I agree with you about DNF, but not too sure it's such a big problem for DYN. I think you can get a decent DYN training session without weights.

- If we're having a DNF session some people do bring neck weights but many (like myself) just take less air in and try to get good buoyancy that way.

- Living in London means lots of people come using public transport straight from work, so the less equipment you carry the better lol

I think in practice those who are a bit more serious about competing do sort themselves out and the rest like me just prefer not to carry around weights etc and just take a bit less air in.

 

[EddieP]

Also the thing about no weights was my fault. I can't use them in a public swimming session so the answers were based on that fact.

 

[Simos]

Also the thing about no weights was my fault. I can't use them in a public swimming session so the answers were based on that fact.

Can you not just hide a couple of kilos of lead in your pockets? Lol

 

[EddieP]

May have to. But it looks like I can use a different pool soon so it won't be an issue (when the water is back in it)

 

[Mullins]

Mullins; Hello Simos. My name is Dave and I can't stay submerged with full lungs :wave

So it's not just me that has bad technique, phew!

One of these days I'll try to get it sorted. Ahh, but what's the hurry...