CNF Technique

[rslomkow]

Just curious about the actual technique of swimming for this event.

Despite any rule controversies it is very clear William T. and Martin S. are world class athletes, able to do incredible things. The question I have:

Why do they have the stroke that that they do?

William T. : http://www.verticalblue.net/movies/wrattempt82m.mp4
Martin S. : http://divefit.com/nastaveni/video/WR pro web best q.wmv

The two big questions for me are:

1) Why no wave?
- Wave being popular in the last 15 years as a small amount of dolphin kick in the hips at the end of the kick during the recovery of the arms. (The Breaststroke Pull, Catch The "Wave": Part II)

2) Why do they glide with arms down?
- William T. actually glides a fraction of a second with arms up, Martin does no arm up glide at all.

All the research says that above arm glide is far more hydrodynamic (see technique for monofin records). I was coached to eventuate the arm forward glide on starts and off the wall when doing breast stroke. We even did under-water practice (horizontal in a pool) and encouraged to extend that pause. If you look at world record breast strokers even sprinters maintain a small pause with arms extended while the kick goes.
(Longer boats are faster)

I do agree that in CNF the arms are far more powerful than they are in breast-stroke because you don't lose as much energy breaking the water with your chest, but it seems like a loss of efficiency not to take the glide you get from your feet in the most hydrodynamic position.

3) Why such a fast stroke cycle?

many CWT records are set with a very relaxed looking stroke (kick) compared to especially Martin's stroke cycle.

I am not a good enough athlete to say what would really make sense. To me it seems like something a bit more drawn out, would retain the speed better. As it stands it looks like the return of the arms is using up power of the kick.

I am very new to CNF, for me getting a nose clip and a pipe mask let me play in this game (without the clip I cannot equalize hands-free)

Any other stroke nerds out there who have some advice for the right way to do CNF?

 

[Mullins]

I think Martin spends very little time training for CNF so his technique is not as polished as Will's. Martin probably just relies on his huge dive fitness. I can do good DNF distances despite the fact that my technique is rubbish, simply because of the dynamic training I do.

Incidentally, waterline length is not a factor underwater becase... there is no waterline. Arms-up is more efficient because it makes your profile more streamlined, but that's different from what they're talking about in that article.

 

[wes]

Mullins,

Nice post and good questions. I will give a crack at it as I have a bit of CNF experience myself and also have watched Martin dive CNF in person, though he has changed his stroke a bit on the video since I saw him in person last.

First, Rslomkow is correct with theoretical fact that wave drag does not affect us when swimming undewater, this is why the same nuclear sub that con do 50 kts on the surface can do close to 90 kts while submerged.

This no wave drag underwater affect, though, is the same for DNF and CNF so doesn't explain the different styles and speed of strokes with DNF usually being very slow and dance like while CNF looks more labored and like they are "sprinting" underwater. The main difference, and its a huge one, is that DNF swimmers are typically weighted to be perfectly neutrally bouyant, while CNF swimmers weight with just enough to enable them to get down to the sink phase of the swim. I use 13 lbs for my DNF training and used 4 lbs for my last 48 M, US CNF national record swim (I'm still pretty immodestly proud of that!!)

The reason for this, and Martin and Will would be similar, is that as you descend on CNF, the air in your lungs compresses and you lose bouyancy and lots of it. Martin has about 12l in his lungs so going down to 80m this 12l shrinks doe to pressure over 4x so ends up being 1.2l big. This loses bouyancy for Martin of about 20 lbs if my math is correct (feel free someone to do exact calcs). So to compensate for this Martin will want to be maybe 10 lbs positively bouyant at the surface so he is only 10 lbs negative at the bottom plate.

This in turn has a huge affect on the stroke. At the surface and off the bottom Martin is in effect first "pulling" down with him a 10 lbs float and then pulling up with him a 10 lbs weight. This means if Martin glides at the start he will quickly start to "glide" backward right up to the surface. This means very quick connected "choppy" strokes to get down and then glidier strokes as MArtin nears near neutral bouyancy and then pure gliding down and the reverse back up. This is also why many people do CNF with only a partially full lung on inhale which minimuzes the bouyancy shift as there is less air (see FRC diving for threads on this or read all posts by Sebastian Murat).

Cheers Wes Lapp

 

[shoutatthesky]

I have been training exclusively DNF for the last 4 - 5 weeks. I felt like having a break from the fins. I find it really rewarding and fun.
The only instruction I have received has been watching videos. Mostly I just try to see what feels best and is most efficient by looking at the tiles on the bottom of the pool to see how much glide I can get out of a stroke.
I started off in this discipline just using a modification of breast stroke until I paid closer attention to some of the styles other people were using. So now it is - push of the wall with arms forward, glide, kick slightly before the stroke of the arms then glide with arms to the side, glide, bring arms forward, kick, glide with arms forward, then repeat.
My arm stroke is pretty much a fully stretched stroke but I see Will T. uses quite a different stroke for CNF with two distict phases - a) pull from top position down almost 90 degrees then the hands spin round so the fingers face the body and 'push' down in a swirling sort of motion. I am sure this is quite a simplified if not incorrect discription. I would love to have detailed discription of what he is actually doing. Hopefully I can attend one of his classes.
Haven't tried CNF yet.

 

[monkeyhatfork]

I was looking into his classes (William T.) as well, maybe if there are some people that have taken his advanced no fins class they could chime in on this thread with any advice/recomendations, how they progressed from the course.

 

[rslomkow]

So the little swirl that shoutatthesky sees with the hands is often taught as part of breast-stroke, to catch the last bit of water.

I went to the pool and had someone video me with my little digital camera and came to the conclusion, Will really does have a really good stroke for the discipline. I do not have a very good stroke (breast stroke has always been my weakest stroke style wise, butterfly my best)

Wes does point out that part of the fast cycle time is because these divers really are over-weighted and that makes sense to.

Two more questions:

1) Why don't either Martin S. or Will T. do the descending glide hands first?

I am talking about the point on the way down when the athletes are negatively buoyant. It seems they would be faster doing a hands up glide (kick yourself off of a wall and see the difference of how far you can make it across the pool, hands up and hands down. It makes a difference in DNF)

I assume that the reason is relaxation, and the trade off for speed vs. relaxation goes to relaxation here. Though it seems like more stretching could made hands up more relaxing. Any other thoughts?

2) What about adding a very small Dolphin kick to the end of the pull, right before main kick and recovery?

My personal tests suggest this is a little bit faster, but I don't know about any more efficient. It evens out the speed a bit more because at the end of the stroke you have very little power, and the dolphin kick produces almost no drag. The idea for this comes from breast-stroke wall starts.

http://www.goswim.tv/vids/kevinunderwater.mov

Again efficiency is less of an issue that pure speed, and here the swimmer is doing a big dolphin kick which finishes as the stroke finishes. Imagine a smaller kick that starts later but finishes at about the same time. Maybe this is just because I have a big belly and it smooth out my stroke a bit and if I was more Martin S. shaped I would have no desire to do itrofl.

Thanks for clarification and thoughts on this!

 

[shoutatthesky]

Awesome video! The undulation of the body is combined with the extension of the stroke down the body. It seems to me this is more efficent as theoretically the longer the stroke the more potential it has.

 

[trux]

1) Why don't either Martin S. or Will T. do the descending glide hands first?

Yes, that's definitely because of the relaxation. Also in dynamic apnea, many bi-finners, especially the slower ones (including some recordmen), swim with hands on the sides in a less hydrodynamic position - that allows a complete relaxation of the upper body and saves oxygen. At higher speeds the drag (growing with a square of speed) prevails, hence a better hydrodynamic position is necessary.

 

[Will]

Why no wave?

Energy efficiency. Try doing a dive/dynamic:
a) just with dolphin kick
b) just with breaststroke kick
and see how far you get with each. It may add speed (fractionally) but is usually used to compensate for an uncontrolled armstroke that bends the body at the waist.

2) Why do they glide with arms down?

Velocity is greatest after the armstroke. Gliding with arms in front requires significant extra work from the shoulders. Hydrodynamics doesn't change drastically (torpedo shapes, like a tuna, have less water resistance underwater than long skinny shapes).
With accurate balancing you should get the same distance in DNF pushing off the wall with your arms up compared to down, and terminal freefall velocity in CNF is more or less the same between the two.

Why such a fast stroke cycle?

As Wes explained, stroke frequency changes with buoyancy.
I would add that depending on dive strategy a more relaxed stroke can be more cost effective than vigorously perfect technique.

I was looking into his classes (William T.) as well, maybe if there are some people that have taken his advanced no fins class they could chime in on this thread with any advice/recomendations, how they progressed from the course.

Monkeyhatfork, we are running one CNF course in November, with the opportunity to continue training free of charge in Dean's Blue Hole afterwards.
As well as working on technique, during the courses I work with students to design the most energy efficient dive strategy for their body type (height & density), target depth, cold tolerance etc. A freediver who was training with me earlier this year developed a dive strategy very different to my own which took him all the way to 65m in CNF.
There are still some places left in the December 3-5 course. Minimum performance requirement is either:
- 25m CNF
or
- 75m DNF and 30m+ CW.

Topics include:
- perfecting CNF swimming and freefall technique,
- exercises to maximise TLC:RV ratio (thereby extending equalisation capacity),
- hands-free equalising & mouthfills,
- CNF training tables to increase hypercapnic resistance (and resistance to CO2 narcosis, if required),
- specific asanas and stretches for CNF flexibility,
and the advanced stuff...
- M.E.E. a formula that determines optimum buoyancy and dive strategy for minimising energy expenditure,
- use of yogic bandhas to diffuse contractions and induce 'infinite regression' of metabolism and heart rate,
- no warm-up diving to maximise MDR,
- psychology: mental anchors, visualisation, positive affirmation and contingent programming of the unconscious,
- meditation: pranayama and brain frequency entrainment (binaural beats).

If anyone is interested in the course they should contact me soon at info@verticalblue.net
Cheers, William Trubridge.

 

[watts]

Very interesting stuff your covering in your courses Will sounds great. mental anchors, visualisation, positive affirmation and contingent programming of the unconscious,
- meditation: pranayama and brain frequency entrainment (binaural beats).
And free Blue hole entry thrown in too. Could you explain about using brain frequency entrainment (binaural beats) in your training and when would be the best time to use this? (Just before a dive) I have done some work with these also and with Alpha and theta tapes.

Nathan Watts

 

[monkeyhatfork]

WOW! thanks for the class info, as of right now my long term plan is to take 3 or 4 courses from different teachers I'm taking PFI first as they offer local classes, but deans blue hole is definatly the next destination, both the class and location look ideal, weather I take the standard course or the CNF special course will depend on my progression-at the moment I still fight with 50m DNF, but I'll probably see you either way sometime 2008

thanks again for the info class/technique.

 

[TRITON]

I heard from Eric that there is a way to postpone the contractions by blowing gently through your nose.......is that what you call infinite regression?

 

[rslomkow]

Energy efficiency. Try doing a dive/dynamic:
a) just with dolphin kick
b) just with breaststroke kick
and see how far you get with each. It may add speed (fractionally) but is usually used to compensate for an uncontrolled armstroke that bends the body at the waist.

Thanks! Watching some video (out of a little compact digital camera) of myself and thinking about this comment I can see the problem my pull is out of control, I will work on it.

Doing a class would be great, but getting the time to do it is always difficult.

Thanks for taking the time to share some tips on the forum for those of us learning this discipline! Also thanks for putting up your high-quality record videos so we can see what technique of the best looks like.

 

[Will]

Hey Nathan, the binaural beats I mainly use in recovery, especially if I have just done a good performance or 3 days of hard training. I often 'wake up' from a session feeling like I've been asleep, but with a conscious memory of what happened during the session.

Alex, blowing gently through the nose has the same effect, but by using the bandhas you don't have to get rid of any air...
It is interesting to observe the intense bradycardia: I have a small ticker and as such a pretty mediocre resting HR (low 50's), but using these techniques I can slow HR down, in the space of seconds, to the point where the Polar monitor discerns the atrial and ventricular contractions as two separate beats(if anyone knows of a monitor that works well at low HR, and can download graphs to the computer then let me know).