Stroke - Frequency or efficiency?
by Bernie Wakefield
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This article was written long before the paper Competition Analysis for High Performance Swimming, submitted by Bruce Mason and Jim Fowlie, which appeared in the May-June edition of the ASC journal. After reading this excellent article, I though very hard about releasing these thoughts on the same subject. These opinions are not about disagreeing with the analysis sheets because the authors have obviously gone to great efforts to produce information that is invaluable to coaches. The reason for contributing my tuppence worth is to point out that we still have a long way to go to reach the ultimate in measurement of efficiency in swimming. It is in no way a criticism of their work in this field.
he latest bandwagon being jumped on at the moment is Stroke-Rate or Stroke Frequency. The word "Frequency" seems to be a replacement of the term "Rate", an expression used by coaches for many years to indicate the power, velocity and length of stroke over a certain distance.
Frequency appears to be now the 'in' term. It is defined as the number of arm cycles that would occur in one minute if the swimmer was to swim continuously over a one minute's duration. To be more exact, it refers to the free-swimming phase only minus turns, starts or finishes. The term, Rate, was probably discarded for that reason but for the purposes of simplicity I shall use both terms as they have the same meaning.
Another designation for a similar operation
also includes those elements of the race. This will be a further subject for discussion later.
Whatever terminology you use, it is well to remember that this idea of stroking for power and length has been around for the last 50 years or more. Coaches have used this image for at least that time to prompt their swimmer into using and developing a 'feel' for the water. The 'Distance per Stroke' terminology a similar teaching ploy is used for exactly the same purpose.
It is not my intention to downplay this idea of maintaining stroke frequency for uniform or increased speed throughout the race distance. Nor do I offer many, or any, suitable alternatives better than this concept. I only want to point out that the answer to sustaining or escalating speed is not as uncomplicated as it seems. The request is that coaches do not apply entirely, that simplistic supposition to every individual swimmer.
I have some reservations on the efficiency index that is being used as a marker in the analysis sheets of the Biomechanists. This figure is arrived at by multiplying the swimmer's velocity by the swimmer's stroke length during that phase called the free-swimming section of the race. My problem is that I find it difficult to accept the precept that stroke efficiency relates only to the equation of a slower stroke frequency coupled with a longer stroke length. At a time when we still have difficulty in pinpointing exactly how propulsion is actually obtained by swimmers, how is it possible to arrive at such a categorical statement? It is not yet even conceivable to measure efficiency of stroke or energy expenditure by any means so correlating it to speed is simply a stab in the dark solution. On the face of it though, it seems to make common sense.
Although the accuracy of measuring the swimmers velocity and length and speed of stroke is not in question, the results given as the index of efficiency is disputable if only because of its imprecise nature. Given the infinite variables that are certain to plague swimmers in their progress through the water it seems illogical to place such total emphasis on such a simplistic notion.
If this is all the measurements we have, then we have to use it and there is no doubt it will be beneficial but it should be remembered that it does not illuminate all of the strengths and weaknesses of the swimmer during the race. It questions only if the stroke, length and velocity were compatible to the speed of the swimmer at certain sections of the event. I am not disputing it is wrong I am debating that there could be many other factors that would govern a loss or gain of speed other than the ability to hold stroke patterns with optimum efficiency
and holding uniform stroke may not be the answer to the problem anyhow.
Measuring individual efficiency while in the swim mode is a difficult if not impossible procedure, and graphs are one way of showing defects in that area. These graphs highlight the distance per stroke procedure to achieve maximum gains. However, efficiency can be improved by other methods other than this formula shown on the graph. It is not the DPS that is the basic requirement but the how fast (and therefore efficiently) that distance through the water can be maintained or increased per stroke. There are a number of ways of accomplishing this without resorting to long powerful stroking. Here are just a few for example:
depth (not length) of stroke for a more powerful stroke
less drag by a improved streamlining
a superior technique of stroke allowing a faster and more efficient turnover
several factors involving a preferred kick
shedding of vortices in the correct plane
Graphs are not always 100% reliable in this respect either. Plotting figures on a graph to display a trend of movement (whether in curves, straight lines, troughs or peaks) can be manipulated to prove any valid or even invalid theories. In this regard they are like statistics
they can be made to fit any occasion or situation.
Comparing stroke length and swimming speed on a specially prepared graph can be shown to prove a loss of stroke length when velocity falls away. By the same logical thinking, the graph can also be adjusted to display too much length, too slow a stroke for that swimmer in the total free swimming distance leading to an inability to maintain speed late in the race, which throws this particular swimmer's efficiency analysis into discord. Any one of a dozen factors could be blamed for the swimmer's lack of speed using the same graph. I have always been suspicious towards graphs for the simple reason that they do not compute the definite reasons for loss or gain of speed merely displaying problems or predictions that are acceptable because they have a veneer of scientific respectability.
I do not believe that these specific graphs are designed for anything else but rule of thumb measurement and should not be used for any purpose other than perhaps a guide to changing training patterns or, relating and making comparisons to other swimmers in the race.
Making figures fit a pre-supposed notion - dogma - target, is a favourite trick of pseudo science and can be compared to a magician sawing a lovely lady in half. What you see is not always what you get.
Even that slayer of scientific dragons and deflatist of pompous cant, Albert Einstein, would have a spot of difficulty with the weak data available to come up with an accurate equation of calculation. His belief-shattering theory of relativity would seem as simple as 2+2=4 when comparing the variables of an energy producing mass in fluid with a mass in space!
Consider relating the passage of an ill designed body, using an inferior and crudely measured stimulus, through moving water that is equally incapable of accurate computation and then trying to present a pure equation to give an exact result! I'm sorry, but I don't buy that - not yet! Nevertheless, until something better arrives, there is no harm in using this imprecise estimation to teach efficiency - so long as it does not interfere with the body's natural function of stroke.
A short time ago I sat beside Joe King at a major meet, and discussed a biomechanical print-out of one of my swimmers from a just concluded heat. Now Joe is a highly respected coach who has served as coach and manager on many Australian teams as well as producing a prolific amount of swimmers for those very teams. We remarked on what a fine job the scientists were doing and how much this information could help us to fine-tune the swimmer for the next race.
On the stroke frequency segment though, where it showed that speed and stroke length had fallen off slightly in the last 15m, he made a statement that was typical of Joe's laconic humour.
"So what do you tell your swimmer," he growled with a wry grin. "Go faster when you get to the 85m mark"?
He was right on target of course because the real answer for future races lay with the 'old drawing board' or, to be more precise, the training pool. Here the stroke is refined and endurance power expanded to maintain the speed and efficiency of the stroke so it would not occur again. Or, if the swimmer had to swim a final later that day, then you had better find very quickly some other way of swimming that last 15m so maximal velocity in that area of weakness could be maintained!
Is rating correctly the way to go for the future? I truly believe so but do we teach our youngsters to increase their pace by increasing the power of their stroke without significantly increasing their stroke rate and at the same time, maintaining optimum efficiency? Or, does it matter how you increase that speed through the water provided the skill of stroke or stored energy is not lost? Is there a clue in that word - energy?
The Biomechanical analysis that sport scientists hand out at National Meets have an explanatory note on the terminology usage and the future direction coaches and swimmers should take as a result of that report. They are so cleverly and efficiently constructed that we coaches now go looking for them anxiously after the heats so we can find an 'edge' to use. However, in the matter of stroke, they seem to have taken the easy option by saying that there is no fight or wrong or even good or bad stroke. I assume by that they mean every coach to their own ways and means of skinning cats, climbing mountains or stroking swimmers, etc.
Their analysis sheet merely identifies each swimmer's weakness or strength in particular areas of the race. In this respect these analysis briefs are of incalculable value. The concept of combining stroke frequency with stroke length and power to obtain the perfect velocity of the race and limb speed is certainly desirable - if it is a possibility. But is it as simple or absolute in theory as that? Or is there a better, less energy sapping method of obtaining that idealism of pace? Or could there be a measurement of efficiency or energy somewhere along the track ahead that will give us a more precise judgement?
My belief is that teaching Stroke Rate is a very clever way of producing very good swimmers who are able to maintain speed or even increase speed by this method. This process of learning and training, will not only expand the required power source to enable this to happen but also refine the neuromuscular pathways to sustain a perfect stroking requirement. However, this essential part of the training procedure may require much research - and practice.
The main weakness in these analysis reports appears to be in the conjecture that velocity is determined by Stroke Frequency and Length of Stroke. Due to the many alternating problems encountered in the water this is not strictly an accurate measurement because efficiency can not be added to the equation with any degree of precision. Nevertheless, this analysing method has been around for some time now and refined by scientists until it has become an invaluable tool for coaches to improve their swimmers stroke and speed.
However, comparing Today's method of analysis with Tomorrow's would be like comparing a T-model Ford with a Cadillac. It is effective, it does the job in a crude way, it's the best we have available and overall, it is a huge improvement on past methods of calculation.
In the looming future there is little doubt we will be able to computerise and assess each individual swimmer's stroke for length, speed, efficiency and energy use and come up with a refined and accurate result. Until then we have to be thankful with what we have.
PROPELLERS - PADDLES - OARS - ARMS?
To fully understand this image I am trying to develop, it may be an idea to equate a propeller on a boat to a swimmer's arms. This has been, in the past, a favoured hypothesis of authors of swimming articles concerning a swimmer's propulsion. It is not a good comparison as the propeller principle involves the propulsion thrust to be at right angles to the direction of motion. And that rules out the assumption of arms being propeller-like. That is, if they are referred to in the sense of comparing aircraft and ship's propellers to swimmers arms. In the literary sense though, the term 'to propel' is quite correct. Feet, due to their similar shape while in the freestyle or backstroke mode of kicking, may be compared to the thrust of a ship's propeller.
So a more appropriate suggestion may be to relate to paddles (as in a canoe) or to oars (as in a racing shell) rather than propellers. While the movement of arms thrusting a swimmer forward in freestyle is not quite the same action as oars and paddles, they are close enough for the purpose of comparison. The biggest difference is the part-loss of 'feel' or sensitivity by these man-made designs of metal, wood or plastic. This means that, coupled with their lack of flexibility, they do not possess the innate ability to fully sense the fluid denseness (viscosity) of water. Without this ability they cannot grasp and thrust the molecular flow of the water in the same degree of focal awareness as human arms/hands can. This may seem to be an abstract idea but it has implications when nearing the point of breakdown of mechanical or biomechanical parts as we shall see.
What we need to consider in the theory of stroke frequency and particularly in holding that stroke rate throughout the race, is the absolute best method of controlling speed - or energy. Which of course means efficiency.
In many scientific swimming articles there seems to be a lack of priority concerning the fluid dynamics of water and swimming when relating to the propulsive stroke - by whatever means. Propellers seem to be the most discussed methods of comparative impetus so let's look at that for a moment. Despite what I said before about comparing propellers with arms, this may still be a good analogy for comprehending the dynamics of fluid distribution.
If you have a boat propelled by that medium, and you wish to increase the speed of the boat, you can attempt several modifications. One is to fit a propeller that is more efficient in its output for that sized boat - and its motor.
Now, here may be the clue for a monumental flaw in certain theories of swim mechanics. The redesigned propeller will increase the speed of the boat - if both motor and design of boat are compatible. However, the propeller size and shape may already be correct for that boat and motor
so what do you do now? Yep! That's right, increase the power source, which is of course the motor.
If, in this case, the size of the propeller had been increased, the motor could have been damaged if it wasn't capable of exerting sufficient power to create maximum thrust at the propeller. Equating that to a human body and what do you have? A broken down swimmer! Unable to maintain pace because the power source (condition, overall body strength) is ineffective for the technically and strength refined arms, the swimmer reverts to a poorly designed stroke that could be aptly described as a 'survival stroke' Another case of tendonitis for the Physio!
On the other hand, if the power of your old motor was capable of handling the new propeller that you fitted, then you could expect an improvement in the boat's overall performance. Just as you would expect a performance lift with a swimmer with whom you had rectified the efficiency of stroke by improving technique or strength if the power source of the body could handle that increased arm capability. And that means an overall proficiency of the swimmer
not just the arms.
Now, by the same aptitude of logic, it must be apparent that if the motor (body) was over-powerful, and the propeller design ineffective for all that force being applied, then damage would rapidly ensue to either the propeller (arms) or connecting joints (shoulder). Marine engineers call this condition "cavitation". Aircraft pilots call it (with all power off) "feathering the prop". Swim coaches call it "spinning the wheels".
So the real answer to large increases in power and therefore speed, appear to be an increase in the capacity of the motor
that is, a reinforcement of technique, vigour and streamlining of the entire body - the power base in all its totality of biomechanical behaviour. Maintaining stroke rate efficiently, may be one of improving speed but there are other applications that are just as effectual in combination - and essential to an enhanced velocity.
Increasing stroke rate without losing efficiency or energy (comparative) is another possibility of maintaining pace. Competitive Rowers use the notion of lifting their rating of stroke at the end of their races. However, it is also possible that they elevate their power expenditure as well. Ultimately, while lifting the stroke rate (velocity of stroke) they are also attempting to increase their speed through the water without a significant loss of stroke length. If they are strong and fit enough, this situation will occur. So why not with the swimmer?
One more method of swimmers enduring or increasing speed just as effectively, is controlling the kick throughout the race so it can be at its strongest for that last 15m. However, all of these means of intensifying speed will also require an improved power base - not just the rectified power or proficiency of the propelling surfaces - the arms.
I warned earlier of damaging the swimmer if sources of power other that the arms were not considered in the maintenance of stroke rate. Strengthening the arms is only part of the equation. The rest of the body must be capable of persisting with the added power provided by the increased efficiency of stroke and improved power of the arms. So, any technical weaknesses in the body (including the arms) must be detected and modified for obvious reasons. Do not lose sight of these other important issues. Several areas that appear to be largely overlooked for strength expansion are the lower abs and the gluts.
It is not just the size, strength or technical efficiency of the propelling factors (arms) but the amount of power being delivered by the power source (the body) that matters most in the quest for more speed.
Here is another widely held rationale that may be of assistance in understanding the forces of motion concerning swim propulsion. This interesting observation is the thought that swim stimulus could be regarded in the same fashion as walking or running. That is; moving the mass of the body over the legs and feet when in this particular mode of motion and using the ground as a base for thrust.
The equivalent form in freestyle swimming is analogous to positioning the propelling members (the arms) in a static position against the water, thus creating force and therefore, forward movement by using the mass of the body in a rotating manner around the long axis. Now this rationale is a well-documented hypothesis and if correct or even partly correct, leads on to theorise that the origin of power does not emanate entirely from contraction of those propulsive members. It comes from every muscle fibre in the entire biomechanical department of the body - and much, much more. For instance, is the kick also providing drive or forward motion while in combination with arm-strokes or is it similar to the blades of helicopter tail rotors -simply there for guidance and direction?
Let's just pause there for a moment because we have now entered another field in which Fluid Dynamicists may have something to say about forward movement in a moving mass of water.
You see, water is not inert while the swimmer moves through it so all those studies just mentioned may be flawed material. Neither is water solid, nor are the propulsive arms in a static position at any given moment. Water begins to move the moment the swimmer propels forward and consequently there is a certain drag force that is inevitable - Resistance.
Propulsion has often been attributed to the Lift-Dominated theory of Bernoulli's Principle. Much closer to the truth though would be Newton's Lift-Drag theories that rely partly on the resistance factors for forward motion. Of these scientific principles however, the first is presently in complete disarray as far as swim propulsion is concerned. Newton's second law of motion regarding the application of force is still valid and his third (every action has an equal and opposite reaction) is definitely applicable to swim mechanics at some point of the stroke. However, it is more important to know the effects of water reaction when a body is propelled through it rather than the propulsive action of the stroke at this time.
The Flow field, as the fluid dynamicists call it, is the moving mass of water created by the propelling members and the body shape and changes form according to stroke efficiency and force applied. The natural viscosity of the water produces effects known as deformation and appear as flow and elasticity. Water actually stretches like an elastic band but does not have the consequent spring back properties, merely a collapsing condition after stretching. Resilient would be a good word to describe its condition.
Perhaps if we guided a swimmer into believing that is how the stroke should feel when applying force - stretching an elastic band of water - we may improve the efficiency and power of stroke. It may be that this perception of the catch, pull and push may be more concise than the old-fashioned idea of catching a solid object and heaving the body forward.
Because of the many variable factors that surround the isolating of our mysterious progress through the water, it may be a long time before scientists come up with a marker or measuring stick to give us a clearer and more precise picture of what constitutes perfection of technique in the swimming positions.
water consistency and temperature
depth of the pool
water in motion around the swimmer
mass and streamlining of swimmer directly related to the forces of form drag
technique and streamlining of swimmer in a particular stroke
strength structure and muscle composition of swimmer
curvilinear pathway of stroke or even kick
timing and synchronising of stroke and kick
measurement and control of vortices as the flow away from the body
conditioning of swimmer, are just a few of the immense difficulties of measurement
Relating back to rowers and comparing their method of propulsion in semblance to the swim propulsion theory and the similarity of running rationale, it can now be seen that there are one or two flaws in that debate. Water is not solid - as it has been pointed out - and no matter how skilled or strong the swimmer, we cannot yet say that the catch, pull and push section of the stroke is anywhere near as effective as the runner who is performing his act against a solid base - not a fluid one.
Further study in this area of stroking efficiency is recommended. Cecil M. Colwin has written extensively on this subject and his thoughts on the mechanics of stroke using the Vortex 'theory' for at least part of the propulsion, should be on every emerging coach's reading list. It is wrong to call it a theory, it is a proven fact of Physics - that is, the physical laws that we exist under in this World - indeed, the Universe.
These vortices can be quite clearly seen in many situations. One of the most observable is at the blades of oars and these swirling jets of water can be easily seen eddying away and conforming to Newton's third law of motion, creating an opposite reaction.
Speaking of rowers, the oarsmen or canoeists have a better model to work with compared to a swimmer. Even though they are working in a fluid substance, they have several things in their favour in comparison to swimmers. The boat they are moving is less heavy, more streamlined and floats a hell of a lot higher in the water. The paddles of the canoeist with the extra leverage from the arms are far more efficient in applying power than a swimmer. The canoeist, although lacking the swimmer's exact perception of 'feel', obeys the laws of leverage that emphasises simply that the longer the lever, the greater the power that can be exerted. Who was it that said
? "Give me a lever long enough and I will shift the World."
Does that mean that the straighter the swimmers arm and deeper the pull, the stronger is the stroke? Definitely true, but again, the strength factor of relationship with boat, propellers and motor still applies.
So where is this particular discussion leading us?
To perform faster by maintaining a certain stroke frequency as the scientific belief requires us to, we will need a swimmer to be
powerful during the stroke movement
highly efficient in the application of technique
possess a long set of levers (blades, propellers, oars, arms)
endurance to hold that superhuman power of stroke throughout the race. Sounds like Alex Popov to me!
Well, he would certainly be the sprint model you would be seeking if you were after all those perfect demands but we do not all possess those beautiful examples of a great sprint swimmer like Alex. And we have to do the best we can with what we have. And if your swimmer is less than that perfect model do we still try and work that formula? Of course not, we have to structure the optimal speed from whatever and whichever way we can. If it is by the scientific model so be it.
DIFFERENT STROKES FOR DIFFERENT PEOPLE
Which leads to an anecdote or two. At the World Short Course Titles a very fast sprinter appeared on the scene who left more than a few mouths open. His name was Francisco Sanchez and he hailed from that well known (?) country for swimming -Venezuela! In statue he was much shorter than the rest of the final field (fractionally over 6 foot) and his high revving, almost thrashing motion was directly opposite to the fluidity of other sprinters. But he was fast! Fast enough to clean up the World in the sprint freestyle events!
Francisco first made his mark in Rio at 19 years of age, winning the 50m event in a smart 21.80. In Sweden, with his characteristic swift start, he demolished the field in the 100m as well. It could be said he won without the big men of Popov and Borges being present but his times were indisputably the best in the World at that time. I wonder if his coach (in the U.S.- Ernie Maglischo) had taught him to be a Popov type would he have gone any quicker? Of course there is no true answer to that enigmatic question but it would seem an unrealistic proposal. He simply did what he does well - goes fast in the best way he can. But have no doubt - as efficiently as he could!
In Australia we have a number of classy male sprinters approaching World Standard whose stroke rate is very high in Freestyle but who still obtain very good results. I seriously doubt they would go faster any other way. In other words their coaches (skilled and wise!) saw the best way and guided them in that direction for top results. My sprinter, Scott Logan is a slow stroker in the Popov mould but it is just as natural for him to stroke that way as it is for Popov. And there is planted the seed for thought. The natural way.
While still keeping the image of the remarkable Popov in mind, at this meet was another extraordinary comparison. I refer to the mid-distance female swimmers Claudia Poll and our own Natasha Bowron.
Claudia, a lady of a height of 1.9 and approaching the length of her male equivalent Alex Popov, won the 400Fs in a superb time of 4min flat for a new WR Excuse me, how silly of me, here I am comparing a male sprinter with a female mid-distance swimmer! Really, apart from height, there is little to compare, for Alex flows through the water in the same manner as any sea creature born in that environment, while the elegant Claudia swims distance with a rapid turn over of stroke and a 2-beat kick - as have many of our former Distance swimmers. But, would you please note, Claudia is also able to swim the 200Fs in a faster time than any other female on this planet! I don't know how fast she is over the 100 but in Japan, prior to the start of the '93 Pan Pacs, I saw her reel off 58s in training swims L/C without apparent effort.
Now, let's look at the other little lady I mentioned, Natasha Brown. Natasha could justifiably be called a giant of the pool but certainly not in the vertical stakes. Her stroking is in the same mould as Popov, long, powerful and graceful - with a potent 6-beat kick. Considering her youth and relative inexperience, she stacked up pretty well against the experienced and much older (and bigger) Claudia in the 400. Then she clearly won the 800 in a very smart time. So, who was right? Who did the most efficient stroke? The answer surely must be, all of them did. Even though size may be a guiding factor to indicate what stroke to use, it is not always the textbook way as this anecdote reveals.
There are many other modern contrasts, the tall Amy Van Dyken, winner of four gold in sprint events at Atlanta and her nearly as quick team mates, height-wise tiny in comparison but powerfully built, Angel Martino and former WR record holder for the 100m, Jenny Thompson. Throw in the present World Champ and record holder, the tall and muscular Chinese girl Jingyi Le and you have a real smorgasbord of different styles and strokes. All swimming identical times over the same distances.
Counting stroke is a drill which every coach in the game of swim training uses to good effect. And will do so far into the future. In my opinion it is more essential to use this drill in the two strokes that require arms moving together in the same plane, Butterfly and Breaststroke.
Butterfly in particular requires the swimmer to finish perfectly on the wall with a full stroke for perfection of race tactics. Counting strokes then, for this discipline should be an essential part of daily routine of training no matter at what speed the swimmer is training. This drill certainly entails the Principle of Stroke Frequency proposed by the sports scientists (within the realms of the swimmer's capacity) and is a definite recommendation by this coach inanities.
I believe it is now possible to measure power output of canoeists and regulate their training accordingly to what suits their body's power capability. If scientists can do this, it is distinctly possible they may come up with a marker to measure swimmers output and plan a method of not only finding the best personal technique for production of power but also best timing in relation to Rating/Frequency. Maybe!
THE VORTEX THEORY
There could be an even be a better way of measuring this efficiency factor. The vortex principle of propulsion. Research is still ongoing into the world of vortices. In the marine field, scientists are finding study of creatures like dolphins, rays, sharks and almost all vertebrate denizens of the sea, depend on the spinning away of vortices from their propulsive members to achieve movement - fast movement! What we need to know is how to control those vortices and in what plane are they to be directed for best results.
Even though the flow of vortices is almost transparent, it should be possible in time, to measure the flow power, the direction and plane that they take as they spin and propel away from the swimmer's body. Little whirlpools of pure power! This may be the final solution in the truth of swimming impetus. Jet propulsion!
Amy Van Dyken, the freestyler previously mentioned, has also swum the 100m Fly S/C in a very quick 57.9, does most of her swimming for this stroke underwater. Her sessions of Fly training consists of swimming no more than 10 strokes of Fly per 50m lap and often reaches a breathtaking 3,000m total! What is even more interesting is that she does her underwater work - on her side! Her coach rightly believes that the vortices streaming away from her legs are almost directly behind when in this position creating an almost perfect Action-Reaction principle and therefore more speed. If she kicked in a vertical plane, her vortices would be bouncing off the water surface or the bottom of the pool and may create turbulence and break up the jetstream. Amy is also a World class backstroker also and is no doubt assisted by these tactics.
So where has all this analytical debate led? What do we deduce from it all? In my opinion, precisely nowhere unless you believe in the equine observation, "Horses for Courses" which of course, easily translates into the aquatic world. Considering that progress is being made using this process of analysing stroke length and velocity, clumsy as it might seen, it is certain that some time in the near future, Biomechanists, working closely with fluid Dynamicists, will be able to feed us computable information for every individual swimmer and this we will be able to convert into valuable training programs that will give us the perfect training model.
Summarising all these facts, fallacies and home-spun philosophies, it seems that the analysis race sheets and graphs do show that there is an optimum length and limb speed that relates to overall swimmer velocity under race conditions. And each swimmer will be different. My belief is that caution should still be exercised in some circumstances that have been clearly stated in this article. In the matter of growing children, particularly adolescents, these graphed situations will change as the swimmers change - growth, strength, technique, etc. - and quite often. So, if you are into graphs, then be prepared for a lot of accumulated and discarded paperwork.
Even with all that data though, that extra touch of magic will still be required from a gifted coach to lift that swimmer into the World of Champions. It may be a bonus however, for the coach to possess a logical mind but it is my view that being able to think illogically may also be a gift.