Dolphin KICKING

[Lynn]

Hello,

I'm getting on my hobby (sea) horse here so I apologise beforehand that I will get carried away on this one...

For all people who dolphin kick, forget all you ever learnt for it is Wrong: you do NOT Kick with a mono (or when swimming dolphin with bi-fins). (Fer cryin' out loud !)

Why ?

Kicking suggests a movement with the legs in which you particularly use your quadriceps and hamstrings (= muscles at the back of your legs) to powerfully flex and stretch your knees, resulting in (hopefully) forward propulsion when swimming.

FORGET ALL ABOUT THAT.

Be honest, have you ever seen a dolphin (or any other marine mammal) kick ?

The trick is to swim with your core, use those abdomen and back muscles, flex with the water. Monofinning is not one of the (pardon me for the expression) 'spastic landlubber sports' in which you generate propulsion (of yourself or an object) by sudden blasts of musclepower. It's all about total body control and feel of the water. Control your streamlining, undulate by 'leaning' on the water, work with it (not against it) for its power is far greater than yours.

How to ... ?

Try different ways of swimming (alter one detail at a time), the water will let you feel which way is best.
And learn from the true masters: watch marine mammals and try to imitate their movements.
And don't worry if it makes you feel clumsy or slow in the beginning, becoming a marine mammal is a gradual process unless you're born as one.

So far for my 'humble opinion' on the dolphin k-word ban).

Dive 'em !

Lynn

 

[efattah]

Depends on your Goal

I also believe what Lynn says about technique, but the hard truth is that I did my 82m record with terrible 'legs only', 'kicking' technique, and from what I have heard, Patrick Musimu did almost exactly the same thing!

So, it is possible to make or break the world record with ugly legs only kicking technique. It may not be pretty or even fun, but it works at least well enough for a world record.

Of course, that's not to say that the better technique wouldn't result in even deeper depths, but if you're not concerned about artistic impression, then the legs only thing seems to work for now...it's also a lot easier to learn.


Eric Fattah
BC, Canada

 

[laminar]

Eric and I have laughed about how my technique is better than his--yet he dives almost 40m deeper than me.

I would say in his and Patrick's case, monofin technique is only one part of the world record equation. Try motivation, breath-holding ability, fitness, confidence, etc...

I'm more in Lynn's camp: monofin undulations as an end in themselves. Feeling like a dolphin, slipping through the water is as fun as going deep. I spent a whole winter practicing my undulations without my fin, trying to fine tune my body. Not because I have a set goal or anything, but because it felt really, really good.

And I left everyone behind in my wake....


Pete

 

[Rhonda]

Good advice Lynn
And Pete, where's that " no-fin technique with the sculling hands" video clip? I would probably learn a thing or two!

Rhonda

 

[Ben Gowland]

Yes Pete - where is that video! My missus wants to see it - she set a new womens UK record of 100m DWOF a month back, and was very interested to see you corkscrewing!

Back to monofinning - I agree with all about the speed efficiency of the undular stoke and use it when swimming laterally and just for fun. However I don't use it throughout a CW dive and this is why:

The undular stroke is more O2 efficient than the leg only stroke, but it uses muscles situated much closer to the heart. Therefore the return of deoxygenated blood back to the heart-lungs-heart-brain circuit is much faster. For this reason I use the undular stoke on my way down, stop kicking at about 30m, sinck the rest and then use the legs only stroke on the way up, with perhaps an undular sprint in the last 20-30m of ascent. The reason being that on descent, you have already shunted a great deal of blood to the core and would like that blood to be as oxygenated as possible. On ascent you want to keep that reserve, and by kicking legs only, you have little venous return from the legs, and end up getting tired legs, and have to go anarobic, once you get really tired - you can change to undulation and get a bit of speed back on your last bit of ascent, but breathe before the deoxygenated blood from your back and abdomninal muscles reathes your heart.

Does that make sense?

I

 

[Alun]

interesting subject

the main difference between standard finswimming and freediving with a monofin is that you're having to deal with changing buoyancy (resistance). this means that it's entirely possible, if not highly likely, that the most efficient stroke in freediving will change during the dive - exactly as Ben has pointed out. when it comes to finswimming--freediving, i believe that 'what is good for the goose (finswimmer) is not necessarily good for the gander (freediver)' in this case.
the other thing is that the standard finswimming position/stroke (from what little i know!) is about minimising drag... since drag increases with velocity squared, this becomes a really big problem when doing over 3m/s. But for freedivers who rarely do more than 1m/s, it is much less of an issue...
standard finswimming stroke and the 'leg-kick' stroke could be considered as two ends of a spectrum - we mustn't forget that there's a an infinite continuum of hybrid strokes inbetween! (i used to be a theoretical physicist - does it show? )


alun

 

[Ben Gowland]

Physics geek

Originally posted by Alun
(i used to be a theoretical physicist - does it show? )

alun

No. You seem perfectly sane to me, now.

Remember, we all have a past.

I used to be a bit
Although this is more like me now (post PhD) :hungover

 

[Alun]

hey! what do you mean 'now'?

 

[laminar]

The Worm

Hey, Ben, maybe your present state is most accurately reflected by that WEIRD GREEN WORM! I like it. It seems kinda introspective the way is sways back and forth.

It may be a while yet before I can put the 'corkscrew' stroke on video. I'm busy looking for work right now.

Congratulations to Fiona--and respect!:king

What you say about the diving sequence is very familiar to me because it's what I use, with a couple of those 'hybrid strokes' Alun mentioned. The first few strokes on the way down and up are leg driven, especially in cold water. But I have to wonder if I save oxygen with technique that spreads the muscle work to my body core. My dive in Ibiza was a good example for me. I was less buoyant than usual (3mm suit) and used an undulation (not quite finswimming, of course) from 5m-30m on the way down and then the whole way up. It was one of the best dives of my life. No contractions, easy recovery, smile on my face. I'm fully aware of all the other variables that could account for it being a good dive. But for that kind of diving it seemed like the way to go.

You have experience in warm and cold water. Do you change your technique at all?

Pete

 

[Ben Gowland]

I am sure that Fiona would describe me as a 'worm' from time to time.....accompanied by some - :naughty and some from me

Yes - good point about the difference in technique between warm and cold water. My thoughts are that diving in cold water is coupled with large bouyancy changes, and increases the need for a hard 'leggy' finning technique. I think that in warm water I would use less of a powerful kick, and start to undulate a wee bit more. In fact, I haven't use a monofin much in warm water yet as last year I intended to use one full time, but wore the ends of my toes off on the first day in Ibiza, and had to switch back to bifins. I found in Ibiza that doing deep dives with a monofin was 'ridiculously' easy, but had to grunt my way through the rest of the trip with the old bifins. So I don't have that much experience to lend advice from.

Ben

 

[iparcell]

What is the average price for a average-good monofin

 

[ukfinswimmer]

Re: interesting subject

Alun,

This is an argument used in open water swimming - that pool and open water swimming are different because there are waves. True but not true. Hydrodynamics do not change at any depth. Indeed, it is more important to be streamlined at greater depth as the density of the water will increase.

Velocity is only one part of the Strouhal equation, the equation that is used to determine drag and efficiency in aquatic movement. The others are surface roughness, apparent cross-sectional area, length to width ratio, medium density (in this case water density) and medium viscosity (in this case water viscosity). Efficiency does not necessarily or particularly mean speed.

Finswimming relies on hydrodynamic efficiency coupled to power, with the former being the most important initial step in the process. The body position in finswimming has been developed to increase efficiency first. By reasoned logic, it is therefore as applicable to freediving as having a good frontcrawl stroke is to openwater swimming.

All the best,

Alaric.

the main difference between standard finswimming and freediving with a monofin is that you're having to deal with changing buoyancy (resistance). this means that it's entirely possible, if not highly likely, that the most efficient stroke in freediving will change during the dive - exactly as Ben has pointed out. when it comes to finswimming--freediving, i believe that 'what is good for the goose (finswimmer) is not necessarily good for the gander (freediver)' in this case.
the other thing is that the standard finswimming position/stroke (from what little i know!) is about minimising drag... since drag increases with velocity squared, this becomes a really big problem when doing over 3m/s. But for freedivers who rarely do more than 1m/s, it is much less of an issue...
standard finswimming stroke and the 'leg-kick' stroke could be considered as two ends of a spectrum - we mustn't forget that there's a an infinite continuum of hybrid strokes inbetween! (i used to be a theoretical physicist - does it show? )


alun

 

[ukfinswimmer]

Iain,

An old fashioned mono should cost you less then £90 (Aus$ 150 - I think). The new style ones should cost from £220 (guess Aus$ 300) up to about £750 (guess Aus$ 1,800).

Alaric.

 

[DeepThought]

Good points Alaric, but one thing that is missing in what you defined "efficiency" is different O2 consumption rates in different body postures.

 

[ukfinswimmer]

Good points Alaric, but one thing that is missing in what you defined "efficiency" is different O2 consumption rates in different body postures.

Physiological efficiency is the ability to carry out the required action with the least amount of energy use per level of performance. In other words, it is the ability to do something better for less energy. Finswimmers learn to use monofins efficiently (i.e. to get faster or carry on at a faster level for longer). This translates directly into low speeds as well; a finswimmer can use a monofin more efficiently (i.e. with less energy/oxygen use) at low speeds as well. This is partly because they develop physiologically, through aerobic and anaerobic adaptation, but mostly because they are better streamlined. Hydrodynamic efficiency is very easy to work out and will be the greater cost/benefit to anything moving through water.

If someone is better streamlined, they will have less resistance over head and be able to operate at a lower energy requirement, thus requiring less oxygen. Oxygen use and physiological efficiency are synonymous in this instance, as a more efficient physiology will use oxygen less. This link is very well established as is the link between heart rates and aerobic training/efficiency.

Alaric.

 

[DeepThought]

What I was trying to point out is that streamlining has a cost and that sometimes it is greater than the benefit, one should search for the optimal combination of both..
What I think you're saying is that EVERY improvement in streamlining is greater than the possible increase in the Oxygen consumption due to actively maintaining body posture.