Myth #4: The reason you keep the elbows high on the underwater pull is to increase power.
I hear this often from both coaches and swimmers. When one looks at the underwater shots of the world’s fastest swimmers, sprint or distance, one finds the recurring position of high underwater elbow, also called Early Vertical Forearm (EVF). The elbows are not just high, they are unusually high…almost in a contorted position with extreme external rotation of the shoulder joint, particularly when coupled with the body rotation in the opposite direction. it begs the question, can one really be stronger in this almost contorted position? I believe the answer is no. To test this, one can go in the gym and using the Free Motion pulleys, that many gyms now have, pull as much weight down with your arm relatively straight forward, then try it with your arm at the side, shoulder externally rotated and elbow up. You will not be able to pull as much weight in that position. With the shoulder fully extended, it is simply not in a good mechanical position of strength.
So if this weird high elbow position is not about power, what is it about? Drag. By changing the position of the arm as it moves through the pull cycle, one can reduce the drag coefficient significantly…not eliminate it. To prove this, kick with fins all out for 25 yards extending one arm above the head and the other straight down toward the bottom of the pool. You will soon learn how significant the drag of your protruding arm becomes when it is at right angles to your long axis. In fact, you will have to work to keep the arm in the position and with any speed at all, it will shake in the water like a palm tree in a hurricane in the Keys. Now try the same drill, but instead of putting your arm straight down, let it protrude straight out to the side but bend the arm 90 degrees at the elbow, as if you were swimming with a high elbow. You will feel considerably less drag in this position. Same arm…different position…a lot less drag.
Now I realize that this is not quite the same as while swimming, when only the upper part of the arm is moving forward throughout nearly the entire underwater part of the pull cycle (In order to cause resistive drag, the object must be moving forward). However, the upper arm is also the largest part of the arm and changing it’s orientation in the water also reduces the drag coefficient.
The good news is that most coaches are telling you the same thing, pull with your elbows high underwater. Now you know the real reason.
In fact, you will have to work to keep the arm in the position and with any speed at all, it will shake in the water like a palm tree in a hurricane in the Keys. Now try the same drill, but instead of putting your arm straight down, let it protrude straight out to the side but bend the arm 90 degrees at the elbow, as if you were swimming with a high elbow. You will feel considerably less drag in this position. Same arm…different position…a lot less drag.
Now I realize that this is not quite the same as while swimming, when only the upper part of the arm is moving forward throughout nearly the entire underwater part of the pull cycle (In order to cause resistive drag, the object must be moving forward). However, the upper arm is also the largest part of the arm and changing it’s orientation in the water also reduces the drag coefficient.
The reason those two example feel different is that you “feel” the moment of force (f*d), not the force itself. It’s why you can hold up a heavy weight much easier if its close to your body, rather than at arms length. The force itself is the same (surface area * drag).
The reason to trim the sails of a boat are to “increase power,” though the sail has ZERO power on its own. But the effect is to increase the forward propulsive force.
Analogous to the swim stroke? Probably.
Just because the position you mention isn’t advantageous in lifting dead weight doesn’t mean it’s not a powerful position in terms of lower ranges of force in a fluid medium.
This topic came up in your prior “Swim Myths” thread, and I assumed you were referring to holding the elbow high when extended out in front during the catch. At that part of the stroke, the frontal area of the upper arm would be reduced, reducing drag on that body part. After watching your video and seeing that you meant that drag would be reduced with high elbow during the middle of the stroke where the upper arm is sticking out at a right angle from the body, I have to agree with the other posters that the frontal area of the arm is the same, and the reason it “feels” more streamlined is that there is a smaller torque arm on the shoulder in this position.
If there really is lower drag in this position, it may be because more of the arm is closer to the body in water that is both more turbulent and moving forward due to the movement of the torso through the water. (In cycling, we would say that the arm is in “dirty” air, and so has less of an aerodynamic penalty than an arm sticking straight out in “clean” air.)
The reason those two example feel different is that you “feel” the moment of force (f*d), not the force itself. It’s why you can hold up a heavy weight much easier if its close to your body, rather than at arms length. The force itself is the same (surface area * drag).
Agreed. Arm straight, or bent, the frontal surface area is the same. Extended versus closed only changes the moment arm and consequently the torque that you experience at the shoulder.
Nitpicking aside, the high elbow reduces frontal surface area, effectively streamlining your upper arm along the axis of motion. I still maintain that the best piece of advice I have received regarding swimming technique was to reach, pull, and recover as though you’re a long body swimming through a very narrow tube. Any movement outside of that hypothetical tube can only slow you down.
The reason those two example feel different is that you “feel” the moment of force (f*d), not the force itself. It’s why you can hold up a heavy weight much easier if its close to your body, rather than at arms length. The force itself is the same (surface area * drag).
Agreed. Arm straight, or bent, the frontal surface area is the same. Extended versus closed only changes the moment arm and consequently the torque that you experience at the shoulder.
Nitpicking aside, the high elbow reduces frontal surface area, effectively streamlining your upper arm along the axis of motion. I still maintain that the best piece of advice I have received regarding swimming technique was to reach, pull, and recover as though you’re a long body swimming through a very narrow tube. Any movement outside of that hypothetical tube can only slow you down**.**
Yah, but that’s only true at the beginning of the stroke, not when the upper arm is sticking straight out mid-stroke. Your “tube” analogy is probably drag reducing. But if you lower arm is inside the “dirty water” tube, it will be less effective in generating thrust. I imagine the ideal position would be minimize the frontal area of the upper arm and keep it as close to the body as possible, while extending the lower arm out into “clean” water during the phase of the stroke where the upper arm has negative speed relative to the surrounding water.
I’m curious why one considers drag on a force generating lever. My assumption would be that for the lever to be providing forward momentum, it must be moving backwards with respect to the static medium. For example, if I am paddling a canoe the paddle moves backwards in the water to generate forward movement for the entire system. The only drag I consider in this situation is the drag in the opposite direction. If, however, I try to move the paddle in forward with respect to the water I only generate drag and do not provide any forward momentum.
It seems to me that the propulsion in the stroke comes while the arm is perpendicular to be body, and based on this first-order analysis must be moving backwards with respect to the static medium. Perhaps there are factors I have not considered. Nonetheless, I enjoy the posts and considering the fundamental mechanics of highly effective swimming brought forth by your mythbusters posts.
I’m curious why one considers drag on a force generating lever…
Gary suggested in another thread that the upper arm is always moving forward relative to the water and that this effect can be shown by attaching streamers to the upper arm.
Nitpicking aside, the high elbow reduces frontal surface area, effectively streamlining your upper arm along the axis of motion. I still maintain that the best piece of advice I have received regarding swimming technique was to reach, pull, and recover as though you’re a long body swimming through a very narrow tube. Any movement outside of that hypothetical tube can only slow you down**.**
Yah, but that’s only true at the beginning of the stroke, not when the upper arm is sticking straight out mid-stroke. Your “tube” analogy is probably drag reducing. But if you lower arm is inside the “dirty water” tube, it will be less effective in generating thrust. I imagine the ideal position would be minimize the frontal area of the upper arm and keep it as close to the body as possible, while extending the lower arm out into “clean” water during the phase of the stroke where the upper arm has negative speed relative to the surrounding water.
I agree that pulling “dirty water” is less effective. However, a good streamlined position (i.e. the tube analogy) will reduce the volume of “dirty water” and minimize the need to extend your arm outward into “clean water”. Obviously, during the pull, there must be some deviation from center, but any excess displacement will inevitably be premature and induce drag.
As I watch expert swimmers, I can’t always see exactly what they’re doing, but I can see what they’re not doing. They’re not plunging their lower arm down into the water, and they’re not brushing their torso. So, based on ralative speed, there’s a happy medium arm position when it comes to drag vs. propulsion. FWIW, I swim 100 scy intervals in the 1:26-1:27 ballpark. A far cry from my 1:38-1:40 of last year, but sufficient proof that I am not close to discovering the optimal stroke.
If you fast forward to :39 you can see their elbow position. Are these high elbows? To me, it doesn’t look like their elbows are that high at all. Is this just because their kick is so strong that they can power through any minor drag issues? Thompson’s stroke almost looks like a windmill through the water.
It would be interesting to compare these videos (sprinting) with someone doing a long distance swim. Your right, the elbows are not high…I wonder if they are when form is more important than power?
You mentioned high degrees of external rotation. Did you mean internal rotation? Externally rotating your shoulder then flexing your elbow would be like a bicep curl.
If you fast forward to :39 you can see their elbow position. Are these high elbows? To me, it doesn’t look like their elbows are that high at all. Is this just because their kick is so strong that they can power through any minor drag issues? Thompson’s stroke almost looks like a windmill through the water.
Thompson looks like he’s “slipping” his elbow at :39. Phelps look “high elbow” to me…but I’m no expert.
In fact, you will have to work to keep the arm in the position and with any speed at all, it will shake in the water like a palm tree in a hurricane in the Keys. Now try the same drill, but instead of putting your arm straight down, let it protrude straight out to the side but bend the arm 90 degrees at the elbow, as if you were swimming with a high elbow. You will feel considerably less drag in this position. Same arm…different position…a lot less drag.
Now I realize that this is not quite the same as while swimming, when only the upper part of the arm is moving forward throughout nearly the entire underwater part of the pull cycle (In order to cause resistive drag, the object must be moving forward). However, the upper arm is also the largest part of the arm and changing it’s orientation in the water also reduces the drag coefficient.
The reason those two example feel different is that you “feel” the moment of force (f*d), not the force itself. It’s why you can hold up a heavy weight much easier if its close to your body, rather than at arms length. The force itself is the same (surface area * drag).
.
There could be more to it than that. It is possible the increased pressure the deeper one is in the water could result in an increased drag for the same aerodynamics. Do the same drill with the arm straight out to the side at the waters surface and I think you would see even less drag. So, you could make the argument that the upper arm, which is moving forward with respect to the water should be shallow to minimize drag and the hand, which is providing the bulk of the forward propulsion should be deep to maximize drag.
I knew this concept would not be easy to understand, particularly with an appendage that changes both shape and direction as we move through the water. First don’t confuse the propulsive drag with resistive drag. The former occurs when an object attached to the moving object is moving backwards in relation to the water. Resistive drag occurs when the object or anything attached to it (like an arm) is moving forward in the water.
The hand/forearm is unusual in that it moves forward at the beginning when it is outstretched (lift position) and quickly changes direction backward as it deepens to create propulsive drag. From the side, the movement of the hand is almost in a circle of about 2 ft diameter, forward, down, backward, up and forward again, releasing in almost the exact same position as it entered. The upper arm is moving forward during nearly the entire underwater pull, thus creating most of the resistive drag of the hand/arm combination.
Changing arm position really does change the drag coefficient. Do the drill I describe and time yourself for 25 yards each way. You will see.
Grant Hacket is a classic hip-driven freestyler with a powerful kick and arguably the highest elbow underwater pull in history. No wonder he was so fast.
Because the elite distance pool swimmers tend to do utterly stupid amounts of yardage/meterage every week to the point of breakdown. It’s how you get to be a player at that level. Even though Hackett reportedly didn’t go to the extremes of an Erik Vendt in the water, it was still high volume- high intensity.
It’s like asking why a runner tended to get hurt while he was consistently running 200 mile weeks.