10 Swimming Myths Debunked

RE: 10 Swimming Myths Debunked

Former Member — Mon, 05 Jul 2010 06:44:47 GMT

The part of this that I personally find interesting is the speed profile data and what it can tell us about swimming. To me the data seems to support the hypothesis that propulsion occurs primarily in the rear quadrant, or at least that propulsive forces outweigh drag forces primarily in the rear quadrant. I'm ready to consider whether "in spite of" what the profile data shows, propulsion is primarily in the front quadrant, but if so it would be nice to have an alternate explanation for the velocity profile. If my analysis of the velocity profile is plausible one can go on to try to determine if the deceleration in the front quadrant is due to high drag or low propulsion. Perhaps some analysis of the velocity of various body parts would be illuminating, e.g. if the rearward hand and/or forearm velocities relative to the body don't exceed the forward velocity of body through the water then they can't possibly be propulsive. Anyway, hard data is so illusive in swimming that I think it is worthwhile taking a close look when some data presents itself, and where hard data contradicts one's hypothesis one should be open to adjusting one's hypothesis.

RE: 10 Swimming Myths Debunked

Former Member — Fri, 02 Jul 2010 14:32:58 GMT

These studies and charts did more to cause and perpetuate the myths I am speaking about than anything else. First, the size of the sideview hand motion is grossly inflated compared to the images. Second, you cannot equate body velocities with power since the shape of the human swimmer and the frontal drag forces change drastically throughout the pull cycle. Third, you must really look at real video images of swimmers (not artist renditions) with the velocity meter and in order to most accurately analyze the arm pull, you must eliminate the kick by strapping a pullbuoy and band on the legs. Since the kick rate is 3X faster than the pull rate, it will throw a lot of artifact into the pulling analysis. Gary Gary, in your opinion. If we focus on 1 arm. Say that we focus on the right arm/hand. Is the peak velocity achieved during the downward body rotation (right shoulder moving down) or during the upward body rotation (right shoulder moving up)? For me, the peak velocity is achieved during the upward body rotation. The timing of the arms is set relative to the body rotation. Where you arm happens to be on the upward body rotation is a matter of taste I guess. I do realize that a lot of role models swimmers (Thorpe Hackett et al.), with their bullet proof shoulders like to extend their effective pulling range by delaying the catch (timing wise), thus grabbing more water. But 1. They still benefit a lot from the upsweep phase and 2. Not sure everyone can afford it. I think you're being a little hard on Maglischo. He's been trying his best over time.

RE: 10 Swimming Myths Debunked

Former Member — Fri, 02 Jul 2010 09:03:40 GMT

It's interesting that good freestyle swimmers have their minimum velocity at the point the hand passes the shoulder because it implies that they aren't achieving net propulsion until this point, despite presumably having an early vertical forearm, thereby giving a clue as to how early EVF occurs. It's only a clue though as we don't know the drag profile. Minimal velocity while the arm is achieving EVF... these phenomenons are tied. While you achieve EVF with the left hand/arm (all taking place in the front-quadrant of course), you're benefiting from the peak velocity achieved with the right arm. This "pull hard with the right arm while gently taking an EVF catch" principle is important since it allows for keeping the catch unloaded (or relatively unloaded). Note (for the record) that Maglischo often blames these drop in velocity on shifts in angle of attack that the hand must do throughout the effective pulling range. The passing of the elbow underneath the body is also a major cause for the drop in speed that's occurring before the upsweep takes place. Gary's point is that the peak power (velocity) can be achieved while the hand/arm is still in the front quadrant. That would imply that this peak velocity is achieved immediately after the catch phase (anything that comes before the catch can, in no way, be considered as propulsive, right?). I don't entirely disagree with this statement. I guess it's possible to achieve a lot of torque on the catch. But for this, you have to delay it a bit timing wise (so that you use the upward body rotation to facilitate power application), and I donno. Maybe for some, but certainly not for me. I prefer to take a catch little sooner, even if it costs me little bit of EVF and certainly little bit of Distance per stroke.

RE: 10 Swimming Myths Debunked

Former Member — Fri, 02 Jul 2010 05:29:55 GMT

I take your point that the velocity graph doesn't tell us the complete story with regard to the magnitude of the propulsive and resistance drag, only what the net difference between the two is. That said, it still seems to me that if maximum velocity occurs when the hand is straight out front and minimum when it comes even with the shoulder you must be slowing down in the period between these points. That implies that resistance drag is greater than propulsive forces during this period. That means that if this portion of the stroke is the most propulsive it is also the highest drag and that drag is winning out in this phase, thus the deceleration. Meanwhile going from the slowest point, as the hand enters into the rear quadrant, to the fastest point, where it exits the water, implies that speed is increasing throughout this period, i.e. propulsive forces are greater than resistance forces. It may well be that the upper arm is causing a lot of resistance drag but this is outweighed by the propulsive force generated by the forearm and hand, and possibly the lower part of the upper arm. It's interesting that good freestyle swimmers have their minimum velocity at the point the hand passes the shoulder because it implies that they aren't achieving net propulsion until this point, despite presumably having an early vertical forearm, thereby giving a clue as to how early EVF occurs. It's only a clue though as we don't know the drag profile. What would be really interesting would be to see the velocity profile for someone doing catchup drill, then we could separate out the contributions of the two arms.

RE: 10 Swimming Myths Debunked

Former Member — Thu, 01 Jul 2010 16:07:04 GMT

I know Ernie...but truthfully, never read his book. He wrote 3 of them. Main features of the technical related chapters is that he classifies each portion of the cycle into phases, backed up with hand velocity analysis and forward velocity analysis. These two are tightly related since one can more easily explain the other. In other words, a hand that is traveling slowly in the water won't explain a peak in forward velocity, especially if the other hand is achieving a peak in velocity in the same time. Each phase along with intermediate steps is illustrated with pictures taken under various angles. He was already doing this in 1980. First, in the stroke cycle, a swimmer will spend approximately 1/2 of the entire cycle time in the front quadrant. The other half will be spent in the back quadrant and the above water recovery. That means we spend approximately 1/4 of the time in the back quadrant... That is a perfect example of one that explains the other. Throughout the pull phase, then hand is constantly accelerating. There are probably 2 main reasons for this: 1. Easier to avoid pulling bubbles and troubled water this way 2. Safer for shoulder muscles in general, since the shoulder is in a vulnerable position with the arm stretched forward (way into the FQ) Therefore your hand will undoubtedly spend more time in the front quadrant(**), being careful taking a safe and efficient catch. Bending the elbow for achieving a little bit of EVF, positioning the arm to pull water backward. Once it reaches near the end of the FQ, Lats are still involved followed later by triceps, your hands travels underwater so fast that it explains why less time is spent during this phase. I agree with you that it's very hard to generate forward thrust during the final release phase, but my opinion, the most propulsive phase of the effective pulling path is the phase that comes before the release, and that comes after the catch. (**) Not sure if I get the definition of FQ right though. For me, this FQ is stops at shoulder level. Passed shoulder level, you're into the back-quadrant. If I got that right, then somehow I'd say that little more than half of the pulling path is propulsive in the front-quadrant, and little more than half of the pulling path is effective in the back-quadrant. The peak velocity being achieved in the back-quadrant. Time wise (since it was your point), lots of time spent in FQ preparing what follows. But what.... Half of this time is lost creating drag and preparing for solid catch, whereas very little time is lost during release phase occurring in the BQ.

RE: 10 Swimming Myths Debunked

Former Member — Thu, 01 Jul 2010 11:38:11 GMT

I'm a little bit confused here because it seems to me that forces (propulsive and resisting drag) correlate with acceleration rather than speed. If minimum speed occurs when the arm is about even with the shoulder that implies that you are slowing down leading into this point, i.e. propulsion forces are less than resistance in the preceding phase, and that you are speeding up in the following phase, i.e. propulsion is greater than resistance. I haven't seen an actual graph to see where the periods of acceleration and deceleration start and end but it seems to me that the conclusion should be the opposite of what was given here. The front quadrant is not more propulsive but is used to position the body for the period of peak propulsion in the rear quadrant, and that if peak velocity occurs as the hand exits then the propulsive phase extends all the way to the hand exit. Is there a graph of the velocity pattern in freestyle available on the web? Have I misunderstood the original argument or gone astray in my reasoning? P.S. Happy Canada Day! :canada: Astray...i'm afraid. If one watches a good swimmer using the velocity meter from side view, isolating the arms (legs tied with a band so as not to confuse the information), one sees a repeatable pattern of fastest speed with one arm outstretched (creating lift) and the other arm about to leave the water. The slowest velocity occurs repeatedly when the hand is about at the shoulder level underwater and the upper arm is at near right angles. The changes in velocity ranges from a drop of 30% all the way up to 50% that occurs in a matter of a few tenths of a second....over and over again. These positions of maximum and minimum velocity should not be confused with positions of maximum and minimum propulsive power, simply because the drag created by the changing position of the arm is so vastly different, these forces are more significant than the power at each position. At the end of the arm stroke, the hand is actually moving forward again (as it was in the beginning), so there is not only no power here, but a small amount of frontal drag. When considering where the power is it is best to consider the physiology of the two regions, when pulling. There is simply much more musculature and mechanical strength in the front quadrant. Gary

RE: 10 Swimming Myths Debunked

Former Member — Thu, 01 Jul 2010 11:21:34 GMT

Yes dear. Here... page 28. Graphs 1.18 clearly shows that Popov is indeed generating his peak power output (and forward velocity as a result of Newton's third) near Point. Fairly consistent with what I know from Popov's stroke (certainly one of my favorite technique shown by world class, as it's very safe for your shoulders). books.google.com/books However, previous pages, Graph 1.17 showing Perkins left arm pulling pathway show a peak when the arm reaches underneath the body. Then page 98 shows peaks that occur across the whole cycle. Biggest peaks occurring on up sweeps. And it's normal, because the upsweep is backed up with upward body rotation. These studies and charts did more to cause and perpetuate the myths I am speaking about than anything else. First, the size of the sideview hand motion is grossly inflated compared to the images. Second, you cannot equate body velocities with power since the shape of the human swimmer and the frontal drag forces change drastically throughout the pull cycle. Third, you must really look at real video images of swimmers (not artist renditions) with the velocity meter and in order to most accurately analyze the arm pull, you must eliminate the kick by strapping a pullbuoy and band on the legs. Since the kick rate is 3X faster than the pull rate, it will throw a lot of artifact into the pulling analysis. Gary

RE: 10 Swimming Myths Debunked

Former Member — Thu, 01 Jul 2010 10:25:21 GMT

Is there a graph of the velocity pattern in freestyle available on the web? Yes dear. Here... page 28. Graphs 1.18 clearly shows that Popov is indeed generating his peak power output (and forward velocity as a result of Newton's third) near Point. Fairly consistent with what I know from Popov's stroke (certainly one of my favorite technique shown by world class, as it's very safe for your shoulders). books.google.com/books However, previous pages, Graph 1.17 showing Perkins left arm pulling pathway show a peak when the arm reaches underneath the body. Then page 98 shows peaks that occur across the whole cycle. Biggest peaks occurring on up sweeps. And it's normal, because the upsweep is backed up with upward body rotation.

RE: 10 Swimming Myths Debunked

Former Member — Thu, 01 Jul 2010 06:57:56 GMT

RE: 10 Swimming Myths Debunked

Former Member — Wed, 30 Jun 2010 16:02:02 GMT

+1 I'm struggling with shoulder issues right now. Fortunately, the MRI I had last week showed no rotator cuff tear as my orthopedic surgeon thought it would. Still, I wonder how much of what I've gone through in the past few months is due to my attempts to improve my stroke, but tried to do things my aging body (I'm 56) simply won't allow anymore. Skip That's one of the huge considerations we incorporate in our clinics, and when we do video analisys recommendations... to offer advice that an individual can attain, without injuring themselves. Musculature, age, overall health and flexibility all come into play for an average individual seeking their PB's, which is the category that most masters swimmers fall into. On can have long term goals, like perhaps building up the upper body musculature so one can sustain the kind of a stroke Gary is talking about, in longer distances. Age and health play a big role in how aggresively one should tackle this. The other, short term goal is to maximize what people do have right now, and make technique corrections (inefficiencies) that will lessen the drag or improve power with what they have now. Shorter, more immediately attainable goals are often things like posture and minor stroke efficiency tweaks. In my personal case, for example, I'm very 'body aware' and can qopt and evem demonstrate various techniques very quickly. When it comes to building power and speed into it, forget about it, I have health issues that prevent muscle and strenght building past a certain level. This is an example of a concern I often have when people focus on the stroke efficiency mechanics in such minutia that they neglect to consider the whole body. Especially when people focus on top level swimmers, and little details of what they are doing, like hand entry, or the S curve or what not... Lot of these things may be adaptations taht top swimmers developed to take best advantage of their individual physique and talents, rather then something that works for everyone. Also, there can be a sizeable difference between working with age groupers and developing bodies and minds, and adults.

RE: 10 Swimming Myths Debunked

Former Member — Wed, 30 Jun 2010 15:36:53 GMT

RE: 10 Swimming Myths Debunked

Former Member — Wed, 30 Jun 2010 14:30:37 GMT

Here's a better pic, of what I think Gary is saying, more drag vs. less drag. (Sorry, don't know how to quote your pic.) I'm not sure this is what Gary is trying to tell us. I think pwolf66 has it correct... No, I believe Gary is referring to keeping the upper part of the arm nearly parallel to the water's surface, just below the surface and the lower arm pointing at the bottom of the pool. The way I interpret what Gary is trying to tell us... The ideal position is to maintain the upper arm parallel to the surface of the water in the direction of forward motion (pointed towards the approaching wall) for as long as possible while the lower arm and hand are moving down during the catch. YouTube has great examples of Ian Thorpe and Grant Hackett doing this. Obviously, this is easier said than done.

RE: 10 Swimming Myths Debunked

Former Member — Wed, 30 Jun 2010 14:19:38 GMT

Can someone add some insight as to what Gary meant by "sweep the arm out" I thought we were suppose to lift the elbow but when I read "sweep the arm" sounds like it isn't recommended to lift up.

RE: 10 Swimming Myths Debunked

Former Member — Wed, 30 Jun 2010 13:28:14 GMT

Again, Gary, thanks for the very helpful discussion. I got back in the water just over two years ago and basically had to relearn freestyle. I found just what you said, that pulling straight back from the initial entry with a high elbow, trying to "anchor" the forearm into the water, then keeping the elbow away from the side in the back half of the stroke is more efficient for me. However the upper arm needs to move during the stroke, mechanically there is no other way. To minimize drag, I could see keeping your upper arm pointed ahead might help, but to accelerate your "anchor" you need to move your upper arm in a way that will maximize the force you can exert. Ian Thorpe does this beautifully, as does Grant Hackett -- both are very efficient and delay moving their upper arms to the side during their pull. Your statement about the release is what I suspected, that you should sweep your hand out (have it act like a wing again) and slide it out of the water. From a fluid mechanics standpoint, it is the difference in velocity that causes drag forces that both allow and inhibit your movement through the water. In a solid, the force is proportional to displacement, in a fluid the force is proportional to velocity. So generating hand speed (and, mechanically, arm speed) while minimizing form drag by good body position should provide the highest peak speed. Great! Now I need to figure out how to swim more than 50 yards ... I'll look forward to further myth-busting! Right you are. People tend to get the propulsive drag force confused with the frontal drag, both acting at the same time. Hand/forearm speed and surface area are what generate the propulsive drag force (propulsive power). Like in many cases in swimming, reaching the optimal position of the arm underwater involves compromise between power and frontal drag. More on this to come. Thanks for your input. Gary

RE: 10 Swimming Myths Debunked

Former Member — Wed, 30 Jun 2010 13:19:20 GMT

Little question for Gary, Your proposal sounds very interesting. However, it goes against that of Ernest Maglischo, who is also known for having stick to the use of both the Forward Velocity and the Hand Velocity monitoring using scientific means, for what.... around 30 years now? How do you explain this difference between your position and his'? In his mind, and fairly consistently across all editions (Swimming Faster 1980, Swimming Even Faster 1993 and Swimming Fastest 2003), the portion of the pulling path that is the most propulsive is the upsweep, which in all cases never begins until you reach mid body line. And quite frankly I do hope that it remains true since the whole arm (from shoulder to fingers) is in a far better position (safer) at this point to apply peak torque. Again, not trying to criticize your proposal here. Just trying to understand the discrepancy that exists between two swimming bodies that both use science to assess changes in velocity. The thing I like about your proposal though, is this suggestion that distance swimmers would benefit from a slightly higher turnover / shorter stroke. Not talking about huge difference here, but 1 stroke or 2 per 25m at a higher rate definitely works well for me. It allows me to keep a better form throughout the event. For instance, I can race most of a full 1500 at 15strokes per 25m (lower turnover rate). It's a huge risk though. Because if I loose a stroke during the event, it is going to be because of technique related muscle fatigue. Then even if I increase the turnover, it's too late. My form degraded. If I start the same event on 17strokes per 25m at higher turnover, no way that my form will degrade. I will finish the event at this stroke count. Easier to achieve even splits in other words. I know Ernie...but truthfully, never read his book. So rather than try to debate him or his philosophy, let me try to defend my position. First, in the stroke cycle, a swimmer will spend approximately 1/2 of the entire cycle time in the front quadrant. The other half will be spent in the back quadrant and the above water recovery. That means we spend approximately 1/4 of the time in the back quadrant...or twice as much time in the front quadrant as the back quadrant. From a practical standpoint, I don't know why we would spend twice as much time in a position of lesser propulsion. Further, from a physiological and anatomical standpoint, there are many more muscle groups acting on arm/hand in the front quadrant than in the back quadrant. In fact, the tricep is about the only muscle still working a the end of the underwater pull. What is a bit confusing is that the body speed is slowest as the arm nears the end of the front quadrant. But this is not because the power is low there. It is because the frontal drag force is so high at that moment from the upper arm...even the higher power cannot overcome the increased drag. Gary

RE: 10 Swimming Myths Debunked

Former Member — Wed, 30 Jun 2010 10:34:45 GMT

(Sorry, don't know how to quote your pic.) I'm not sure this is what Gary is trying to tell us. I think pwolf66 has it correct... There are two different instances where Gary is talking about arm sticking out. One is in the full stroke, where the arm is extended forward having least drag. That one is a bit of a no brainer. That's not what I was trying to illustrate. The other part instance is where he was explaining to Scott what happens during passive drag, just as an argument for bent elbows, one with arm extended out at 90° having more drag, vs elbow bent at 90° having less drag. It's the second one I'm trying to figure out what he meant.

RE: 10 Swimming Myths Debunked

__steve__ — Wed, 30 Jun 2010 09:40:16 GMT

Propulsion (power and acceleration) and speed (velocity) are different things, and the swimmer's max values for each occur at different points. Furthermore, peak drag happens shortly after max speed and if your mortal, and can't maintain speed efficient enough through this point, then your better off minimizing towards the front quadrant for efficiency. Was that the main point?

RE: 10 Swimming Myths Debunked

KEWebb18 — Wed, 30 Jun 2010 08:52:02 GMT

So how does one incorporate this into a drill?

RE: 10 Swimming Myths Debunked

Former Member — Tue, 29 Jun 2010 16:34:00 GMT

Just remember that the hand moves very little in the water during the underwater pull....in a circle of about 2 ft diameter. Gary Are you saying that from start of the catch/pull to the release point, the arm only moves about 2ft?? So, it would feel like the catch would start way out front and that one should release the water as the pulling arm travels past the shoulder area?

RE: 10 Swimming Myths Debunked

Former Member — Tue, 29 Jun 2010 15:15:31 GMT

But it is not because of the power out the back that we see the speed highest in this position. It is because it is by far the position of least drag (most streamlined). The propulsive power in this position actually is derived mostly from the left arm out in front and the kick, with little or no power coming from the end of the arm pull. The propulsive power may be even greater when we see the hand at the shoulder (slowest body speed), but because the arm is jetting straight out, perpendicular to the body, the drag coefficient skyrockets and our speed drops instantly. If this position is the where the highest speed is attained then what difference does the explanation make? What am I not understanding? One could easily draw this conclusion: focus on drag reduction more than power generation to increase your speed. But either way, I also have a problem with the explanation. I have a home-made Velocity meter (don't ask). If I do one arm freestyle with a pull bouy (thereby eliminating the power of the opposite arm and the kick) the results are the same: I go my fastest at the end of the stroke.

RE: 10 Swimming Myths Debunked

Former Member — Tue, 29 Jun 2010 14:18:14 GMT

In addition to a plot of velocity against time, a plot of the first derivative of this would also be interesting. This gives the slope of the graph, i.e. the acceleration. To me, knowing where in the stroke you are accelerating and when you are decelerating might be more interesting than velocity. Man, I've had more opportunity to use my math degree in the last week on this message board than I've had in 15 years in the working world.

RE: 10 Swimming Myths Debunked

Former Member — Tue, 29 Jun 2010 12:42:00 GMT

Your statement about the release is what I suspected, that you should sweep your hand out (have it act like a wing again) and slide it out of the water. ! Can someone add some clarity or pictures of this idea? I have always been told to push back toward my suit, but now it seems that people want to not push so far back?

RE: 10 Swimming Myths Debunked

Former Member — Tue, 29 Jun 2010 12:04:21 GMT

Here's a better pic, of what I think Gary is saying, more drag vs. less drag.

RE: 10 Swimming Myths Debunked

smontanaro — Tue, 29 Jun 2010 11:04:10 GMT

Drastic alteration of a stroke pattern at 45 has a whole new set of considerations compared to changing at age 20. So I tend to try to focus on small changes instead, for better or worse. +1 I'm struggling with shoulder issues right now. Fortunately, the MRI I had last week showed no rotator cuff tear as my orthopedic surgeon thought it would. Still, I wonder how much of what I've gone through in the past few months is due to my attempts to improve my stroke, but tried to do things my aging body (I'm 56) simply won't allow anymore. Skip

RE: 10 Swimming Myths Debunked

Chris Stevenson — Tue, 29 Jun 2010 10:51:28 GMT

The upper arm is truly moving forward during nearly the entire underwater pull and is responsible for most of the frontal drag of the arm/hand combination. ... The increase in frontal drag caused by the protruding upper arm moving forward is extremely high. Yes, I can see that. Actually I think that just breaking the streamline position and "exposing" the shoulder would probably cause a huge increase in drag due to a change in fluid flow pattern around the swimmer. My big (potential) problem with serious training to increase EVF at my age is the possibility of injury due to more strain on shoulder and possibly elbow joints. While my stroke is very far from perfect, I've been using it for almost 40 years without injury, and I worry about the effect of a drastic change on that track record. Drastic alteration of a stroke pattern at 45 has a whole new set of considerations compared to changing at age 20. So I tend to try to focus on small changes instead, for better or worse.