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Kettlebell How fast do we swing Kettlebells?

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Had an idea -- Pavel M. is handy with the camera and plays with shadow swings regularly.

@Pavel Macek , would you be willing to video a set of shadow swings for a speed analysis? It's pretty easy -- camera at hip height, tape an white "X" on the kettlebell, go to town. :)
 
Manuel Fortin said:
I will try to analyze Al's video when I get a chance. I am not sure that this will work as the shadow swings seem to be pretty fast, and I feel that the kettlebell will be really blurry when I look at the video frame by frame. This type of video analysis usually uses high speed cameras and highky visible markers on the points we track from frame to frame. In the present conditions, locating the center of the kettlebell may be a bit difficult. We'll see.

I will be on vacation for the next two weeks, and that means less time spent at my computer, so it may be a few days before I get to that.

Al, how tall are you, so that I can callibrate distances in the video?
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Just under 74".
 
@Anna C sure why not! X on side, bottom? Shoot from side/front? Regular speed?
 
Excellent! Yes, white X on the side of the bell, video shot from the side at 90 degrees to camera, a meter stick in the picture if possible for most accurate calibration (close to you at the same distance to camera). Video such that kettlebell is visible throughout the swing except when it passes between the legs. Seems that a set of 5 is plenty. One set at regular speed, 1 set of overspeed/shadow swings.

I am hoping that Manuel can analyze them, but if he gets tired of it, I will try it myself. I watched the video tutorial on the analysis software and it does look like fun...
 
@Anna C I can do it, but if you want to give this a try, have fun. I am getting pretty good with the software and analysing one swing takes me a few minutes now. We can both do it and compare results. You will see that at high speed, everything is blurry and marking the center of the kettlebell becomes a guessing game.
 
For those still interested in this thread, you can read Science of the Swing. It describes force plate data acquired when people with very familiar names were swinging a kettlebell, and is probably where the numbers cited in S&S come from.
 
another approach to this measurement might be to attach a small, firm force sensor pad to the inner handle of the kettlebell while swinging it.
 
OK, I looked at the swing video by @aciampa and got the following results: regular swings, max speed is 4.5m/s (10 mph) and max acceleration is 3.5g. shadow swings did not achieve higher values, but the max (both speed and acceleration) was held for longer. These numbers are minimum numbers as Al is a bit twisted relative to the camera, which introduces some errors. However, the twist is small enough that I would not think that the error is much larger than 5%. (For those interested as to the reason why, it's because we are projecting in the plane of the camera and the projection is a cos, which does not vary much from unity for small angles) Also, the kettlebell is really blurry and is almost completely lost in between the legs. This is a major source of possible error. A device such as the one linked too in my previous post would probably be the best way to analyze all this.
 
This seems about right.... As I mentioned earlier, I do the shadow swings as Al does, putting the extra effort on the turnaround at the top.

Defining the distinctly different shadow/overspeed swing styles:

A) An explosive upswing just as the default "floater" swing, but arrest the ascent below the natural top of the swing, and forcefully direct the kettlebell down. The kettlebell descends slightly more quickly into the hinge. (Al's description from the Military Deployment Prep article: “A proper swing is a tug-of-war between the opposing body lines: posterior v. anterior. The glutes, hamstrings, and quads forcefully catapult the bell forward, while the lats, abdominals, and hip flexors catch it and throw it back—compress the posterior spring, fire the spring, compress the anterior spring, fire that spring, then do it again. Both the hinge and plank position are maximally tight—maximum feed-forward tension—for the time the bell spends flying out, one is “relaxed- tight”.)

B) An explosive upswing just as the default "floater" swing, allow a float at the top, and as soon as the kettlebell starts its descent, actively push it as hard and fast as possible into the hinge, resulting in maximum descent speed and maximum force at the bottom of the hinge. (Pavel's description from S&S: "Hike the bell back with all-out acceleration and aggression.")

C) I suppose it's possible to try to do both A and B, but I suspect that the effort at the top may compromise the effort in the backswing, and vice versa.

So what I usually do, and what I think Al does, is A. So I just did some experimenting with B, doing some experimenting with a 16kg, 2H swing. That is, letting the bell float to the top, and then throwing it back down as hard as I could. This is COMPLETELY different from any swings I've ever done before, and the kettlebell is travelling quite a bit faster and generating more force at the bottom of the swing, no doubt. Surely the G forces are more on the way down and at the bottom of the swing than what I did before. I don't think I could do this effectively with 24kg, but 16kg feels a little light... perhaps 20kg is the optimum for me. I may practice this a bit more, and video that if it feels like I'm getting somewhere with it.

Looking forward to Pavel M's video. A question for you, and for anyone else: Which of these methods would you say describes your "shadow swings"?
 
I always did B for my shadow swings. Beware how sore your hamstrings will ne the next day!
 
Anna C said:
This seems about right.... As I mentioned earlier, I do the shadow swings as Al does, putting the extra effort on the turnaround at the top.

Defining the distinctly different shadow/overspeed swing styles:

A) An explosive upswing just as the default "floater" swing, but arrest the ascent below the natural top of the swing, and forcefully direct the kettlebell down. The kettlebell descends slightly more quickly into the hinge. (Al's description from the Military Deployment Prep article: “A proper swing is a tug-of-war between the opposing body lines: posterior v. anterior. The glutes, hamstrings, and quads forcefully catapult the bell forward, while the lats, abdominals, and hip flexors catch it and throw it back—compress the posterior spring, fire the spring, compress the anterior spring, fire that spring, then do it again. Both the hinge and plank position are maximally tight—maximum feed-forward tension—for the time the bell spends flying out, one is “relaxed- tight”.)

B) An explosive upswing just as the default "floater" swing, allow a float at the top, and as soon as the kettlebell starts its descent, actively push it as hard and fast as possible into the hinge, resulting in maximum descent speed and maximum force at the bottom of the hinge. (Pavel's description from S&S: "Hike the bell back with all-out acceleration and aggression.")

C) I suppose it's possible to try to do both A and B, but I suspect that the effort at the top may compromise the effort in the backswing, and vice versa.

So what I usually do, and what I think Al does, is A. So I just did some experimenting with B, doing some experimenting with a 16kg, 2H swing. That is, letting the bell float to the top, and then throwing it back down as hard as I could. This is COMPLETELY different from any swings I've ever done before, and the kettlebell is travelling quite a bit faster and generating more force at the bottom of the swing, no doubt. Surely the G forces are more on the way down and at the bottom of the swing than what I did before. I don't think I could do this effectively with 24kg, but 16kg feels a little light... perhaps 20kg is the optimum for me. I may practice this a bit more, and video that if it feels like I'm getting somewhere with it.

Looking forward to Pavel M's video. A question for you, and for anyone else: Which of these methods would you say describes your "shadow swings"?
Click to expand...

I have always done unassisted overspeed eccentric swings like case B, float then hike extra hard, since it is closer to how I learned to do overspeed eccentric swings, with a partner. I have also done a lot of overspeed eccentric swings assisted by a jump stretch band.

With a partner, you get the full float. The partner doesn't touch the bell until the apex of the float or even an instant later, and then forcefully pushes the bell down.

With a jump stretch band, you get little or no float, depending on bell size and band tension. The band brakes the bell on the way up and then accelerates it on the way down.

Neither of these is exactly like cases A, B, or C described above. You are never purposely braking the bell on the way up (the bell does GET braked by the band, but not by any effort of the lifter). and you don't really purposely hike the bell more forcefully. The bell GETS hiked more forcefully, and that force has to be absorbed by the lifter, but the extra force comes from the partner or the band.

Not sure how much, or if, this makes a difference in training effect.
 
Interesting additional cases, there, Steve. Let's add these definitions:

D) partner assisted overspeed eccentric swings

E) jump stretch band overspeed eccentric swings.

As you said, there is no additional effort in reversing the bell at the top or hiking it back, but the additional force is absorbed at the bottom. I have done the partner thing a few times, but don't really understand the purpose. I have never tried the band.

Certainly both of these would increase the G forces on the way down... but are we any closer to finding the elusive 10G?

I'm still thinking the best chance for it would be a well developed "B" swing with the optimum weight.
 
Method A. But I'm going to try Method B now it has been described so clearly

I also tried spiking my one hand swings with the other hand to try and correct torso twist. Did this a few times, but this just felt like it was compromising everything
 
I hope you all don't mind me digging up this old thread. I have been pondering about this idea for the last day or so based of something that came up in the reddit kettlebell forum. I have been thinking this not so much in how fast but rather how high the kettlebell goes with a swing.

On the extreme end of the spectrum are the World's Strongest Man competitors who do a kettlebell toss where they have to hurl the kettlebell over a 5.5 meter clearance. Here is a video of Brian Shaw (2015 winner) I figure doing some BroPhysics that the kettlebell becomes a true projectile at about 1.5 meters up so it has to go up 4 meters and the minimum velocity required would be about 20 miles per hour. Any slower and the kettlebell won't go high enough to clear the bar. If the athlete is accelerating the kettlebell for a half second to get to 20mph he is accelerating it at an average of 1.8G. At a quarter second 3.6G. At an eighth of a second still under 8G. Watching these kettlebell tossing videos it looks like its somewhere between a 1/4 and an 1/8th of a second.

I am trying to figure out of all of the kettlebells I own, which one do I swing with the most force. The 40kg? The 32kg? the 28kg, or 20kg, or even 16kg. I notice the one that will actually get me a tad sore is ironically the 16kg when I just swing it with maximum velocity. I was thinking of an experiment I could do (not that I will, but that perhaps would work. This experiment could be dangerous to myself and property) but it was to grab my various kettlebells and then swing toss them and measure the various heights I am able to achieve, calculate the distances traveled and therefore the velocity that the kettlebell left my hands out to figure out the kinetic energy of each kettlebell and thus figure out what weight I was actually applied the most force on.

I notice that the difference between swinging the 32kg vs the 40kg is that the 40kg doesn't go as high. The 32kg I get at eye level. The 40kg, not so much. Therefore its not going as quick as the 32kg and breaking it down I may have actually applied more force to the 32kg than the 40kg. I also noticed that for S&S practice that it is significantly harder and more draining to do my swings to where the kb goes up to my chin or eye level than to some height that is under my pec. The difference is that the kettlebell is going about 70% the velocity and because kinetic energy is a function of V^2 the difference in kinetic energy is roughly half. It takes twice as much force to swing a kettlebell 1 meter vs .7 meter. So if you cut back the height the kettlebell rises to just a little bit the energy efficiency goes up drastically per swing.

In terms of kinetic energy a 16kg kb traveling twice as fast as a 32kg kettlebell has double the kinetic energy.

The 10G figure I presume is for an absolute split second. 10G for 1/10th of a second would propel an object from 0 to 22 miles per hour and at that rate the kettlebell should clear the WSM posts and those guys are taking longer than 1/10th of a second to accelerate their Kettlebell up.
 
I think S&S says that 1/3 bodyweight is the sweet spot for most people for maximum power production in the two-handed swing.

-S-
 
Manuel Fortin said:
Let's see. The OP mentions remembering high school physics, so should be able to follow this. Don't hesitate to ask questions if this is not clear. I will try to keep the response brief. First, average speed. As an approximation, a kettlebell travels along a curve that approximates a portion of a circle, an arc segment. Let's approximate this as one third of a circle on the way up, and the same on the way down. doing 10 swings thus has the kettlebell traveling along 10 X 2 / 3 = 6.6 complete circles. What is the radius of the circle? My arms are 28 inches long and the kettlebell handle and ball add about 6 inches for the distance between pivot point and center of mass, for a total of 34 inches. Since I am used to the metric system, I will approximate the radius of the circle along which the bell travels to .85 m. So, for a set of 10 swings, the bell travels 2 X pi X 6.6 X .85 = 35 m. A set of 10 swings takes between 15 and 20 secs, depending on many factors. Let's use 15 secs. In 1 min, the bell travels 4X35 = 140 m. In 1 hour, 60X60m = 8.4 km, so a kettlebell travels 8.4 km in one hour, or about 5.2 mph. Of course, there are a lot of approximations and assumptions and the real answer may be 4 or 6 and will depend on a lot of factors.

Now, that was probably not the question. The question seemed to be for maximum speed. Here again, we can get an approximation using physics. Once past vertical, the bell leaves the body and moves with no force except gravity doing work on it. This assumes that the force exerted by the arm is only radial, perpendicular to the movement and thus does no work. In this case, the potential energy gained by the kettlebell from bottom to top is equal to the kinetic energy of the bell at the bottom of the swing. Assuming that at the end the arm is parallel to the ground, and using the same approximation for radius of movement used above, .85m, we have g h = .5 v^2, with h = .85m, g = 10m/s/s, and solving for v: 4.12 m/s = about 9 mph.

Of course, this is all very approximative, but the order of magnitude is about 10 mph for the maximum speed. Also, this is good because it makes sense when compared to the first calculation regarding average speed.

I would be curious to see what video analysis would give. If someone has the right software, it should not be difficult to get a video from Youtube and measure the distance traveled by the bell between two successive frames. I also think that there exist devices you can attach to a kettlebell that include an accelerometer, and integrating this data would give speed.
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I get the feeling you are a lot better at Maths and Physics than me..lol.
 
@Pinkninja I majored in physics, and even started a masters in theoretical physics before I got back to my senses and realized that I wanted to get employed eventually at a reasonable wage. I also studied biomedical engineering and my masters in that field was in part about analyzing movement. These questions are straight in my area of expertise.
 
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