10 Swimming Myths Debunked

I agree. More on the kick later. But I don't agree than just anyone can develop a strong kick. Unless you have strong legs, big feet, hyperextended knees and ankles that are as flexible as threads, you likely won't be kicking very fast. So, instead, concentrate on another way of getting the job done fast...with a high stroke rate and strong pull. Gary Sr. You are right. Velocity does tell the whole story between propulsion and drag, but I insist you must work on both. As far as the frontal drag being the greatest as the upper arm is perpendicular to the body, first realize that this (at this moment) is the only part of the arm moving forward (an absolute prerequisite to create frontal drag). Second, all you need to do is compare the amount of drag you experience pushing off the wall with your arms streamlined in front vs the arms straight out to the side. It is a no-brainer. Gary Sr.

But even granting what you say: why is *propulsion* (alone) everything? You highlight the effects of BOTH propulsion and drag, and yet insist that we should focus only on increasing propulsion. If, as you state, the end of the stroke is when we experience the least drag and highest velocity, why should it be cut short? Just from from fluid dynamics in general.... Assuming decent stroke efficiency to start with, reducing drag has most effect while you still have propulsion. You get very little benefit of trying to reduce drag if it comes at the expense of more propulsion. If I understand this correctly, what Gary is telling us the most propulsion in the stroke happens between hand entry to about about half ways down the body. From fluid dynamics, I can tell you, once you grab that initial handfull of somewhat inert water in front of you, and start pulling on it, and it starts moving with the hand, the force vectors that you can get out of the static water, vs moving water start diminishing, and you get less forward movement. You can test that anywhere, even in a bathtub. If the water is static, and you need to get it going (in a circle with your hand), you have to push a bit harder at the beginning. Once the water is already going, you can't get as good of a push out of it, or you would need to paddle a TON faster to get the same kind of a push. The speed at which a human can paddle forward is not infinite, so after we pulled as fast and hard as we could, and that water around you is moving, what you can pull and push against to move yourself forward diminishes.... You literally end up with less you can grab onto and push against to get the forward movement. At a certain point, the return you get diminishes to a point where you're better off starting the recovery process, then continuing to push. It would be interesting to see more measurements and research on this, with people of varying body structures and competing levels. I would think the stronger and more efficient front quadrant grab and pull are in a swimmer, the less benefit they get from the second half of the stroke. Often, getting to the ultimate efficiency and physical shape is only half of the battle. The other part is maximizing what you do have, and not getting injured in the process.

The Velocity Meter that conducted all the measurements on Gary Sr. can be viewed at the TeamTermin Sports Performance web site, by clicking on the Velocity Meter tab.

Just from from fluid dynamics in general.... Assuming decent stroke efficiency to start with, reducing drag has most effect while you still have propulsion. You can test that anywhere, even in a bathtub. If the water is static, and you need to get it going (in a circle with your hand), you have to push a bit harder at the beginning. Once the water is already going, you can't get as good of a push out of it, or you would need to paddle a TON faster to get the same kind of a push. The speed at which a human can paddle forward is not infinite, so after we pulled as fast and hard as we could, and that water around you is moving, what you can pull and push against to move yourself forward diminishes.... You literally end up with less you can grab onto and push against to get the forward movement. At a certain point, the return you get diminishes to a point where you're better off starting the recovery process, then continuing to push. It would be interesting to see more measurements and research on this, with people of varying body structures and competing levels. I would think the stronger and more efficient front quadrant grab and pull are in a swimmer, the less benefit they get from the second half of the stroke We have tested thousands of swimmers with our Velocity Meter/Video of all ability levels. It has quietly been in active use for more than 20 years. It takes 1000 data points a second of of velocity telemetry to reveal the variations in velocity Gary described during one stroke cycle. Gary"s descriptions come from taking the time to have his swimming objectively measured. When it comes to human locomotion in the water, the analogies verses the findings revealed by the velocity telemetry, are not always in alignment.

We have tested thousands of swimmers with our Velocity Meter/Video of all ability levels. It has quietly been in active use for more than 20 years. Oh, very nice! When it comes to human locomotion in the water, the analogies verses the findings revealed by the velocity telemetry, are not always in alignment. I'm not too sure what that means? Are you talking about anologies that one would come up using what is known about fluid dynamics, or something else? Are any of your findings published? I'd love to read and get up to speed with what you guys are doing. Sounds very interesting :) Edit, I think I found you guys: http://www.teamtermin.com/ ? Interestig stuff :)

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.

Don't spend so much time thinking about your hand, ... With the hand, relax it on the recovery (soft hands) and spread the fingers slightly under water, so as to increase the effective surface area. ... Gary Sr. Gary - Many thanks for including that small tip about the slight spread in the fingers. I spend an inordinate amount of time "untraining" swimmers who have been taught to use the "cupped, tight" hand. I invariably win them over with some in-the-water physics lessons, but it's nice to have a quote from the likes of you to back me up on this for thie parents! Matt Storti

This is also an interesting and a very long technical read: www.fade.up.pt/.../01.swimming_biomechanics.pdf (caution, 2Meg 100 page PDF)

Don't spend so much time thinking about your hand, but preferably your elbow or upper arm. From the side view, the hand moves in a small circle (about 2 ft diameter) underwater. At the beginning, as the hand/arm are moving forward, they act like a wing and provide lift. As the hand drops down it quickly changes direction to move backward and acts like a paddle. Finally, as it releases, it moves forward and upward again, trying not to induce any more frontal drag, sliding out of the water. The bad boy in all of this arm/hand action is the upper arm, which is moving forward nearly all of the time (underwater). So the longer you can keep the upper arm in the line of motion, the better. With the hand, relax it on the recovery (soft hands) and spread the fingers slightly under water, so as to increase the effective surface area. Once the hand gets past the shoulder (under water) the power drops off quickly so release it and get it back into the power position (front quadrant) asap. Finally, in the sagittal plane, don't use the sweeping S-shaped pull of the past. As your body rotates, keep the arm to the side, with high elbow, and pull more or less straight back. You will have minimal movement of the hand in this plane (perhaps 8 to 10 inches) but no more. Hope this helps. More on the underwater stuff to come. Gary Sr. 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!

It takes 1000 data points a second of of velocity telemetry to reveal the variations in velocity Gary described during one stroke cycle. Gary"s descriptions come from taking the time to have his swimming objectively measured. That's all well and good, but what I am not so sure I accept is the explanation Gary proposes for those velocity changes in terms of propulsion vs drag. I don't accept the "no brainer" analogy of pushing off a wall with a perpendicular arm, vs the drag that same arm exerts during swimming. During the arm cycle, is the arm truly moving forward (creating reverse drag) relative to the surrounding water? Put pressure sensors (or some such) on the forearms and check. Let me be clear that I agree that the front quadrant is where much of the propulsion comes from, and that a higher turnover creates more velocity. That is clear from watching sprinters. What is less clear -- to me at least -- is if a higher turnover is the most energy-efficient way to swim a distance event. This is why the question of drag is important.