Kettlebell After 4+ years of S&S

[barrak]

My guess is mass times acceleration.

Actually, mass times gravity is the static loading force, always pointing down.
mass times square of swing velocity divided by arm-bell lever is centrifugal force, always pointing along swing arm.

At bottom (probably fastest) position, they add up algebraically. A lazy swing will make the bell feel like 1.5 times its weight (1.5g).

S&S 2.0 book (p. 96) reports measured 10g swings with a 24K bell, making it feel like a static 240K weight!

Us mortals can probably muster 3-5g.

Those who do silly T-Rex swings stand to lose a lot of loading effect.

 

[Kozushi]

Excellent post. But I have to ask: where do you get the virtual weight of a one-handed 32 kettlebell swing being 100kg?

From posts like the one at the top of the linked page. I'm being a bit inexact with the calculations, and of course keep in mind that the 3X virtual weight is only there for a brief instant at the bottom of the swing. Here is one good quote from the forums:


"According to The Splat Calculator - A Free Fall Calculator, a 32k kettlebell falling .8 meter from the rack to the backswing generates 250.88 joules of force. This site (Joules to Foot-pounds Force | Kyle's Converter) says that 250.88joules is equal to 185 foot pounds of energy."

Kettlebell - Calculating the Physics of a Kettlebell Clean

I have a question regarding the physics of a kettlebell clean. I understand that it takes 32k of force to lift a 32k kettlebell. That is, to deadlift it without adding momentum to the weight. In the clean, however, the weight is dropped from the rack, then pulled ballistically back to the...

www.strongfirst.com

185lbs is actually 84kg, so a bit under 3X the weight of the 32kg kettlebell we're swinging. But I do think the physical math gives us a pretty good if rough idea of how much heavier we're making the kettlebell by swinging it. Of course, at the top of the swing the virtual weight is reduced to less than the 32kg we started with! I wonder what it is up there? Maybe like 1kg, haha!

Especially skilled people can make the bell even heavier than 3X:

Barbell - Questions about PTTP

That's great! I've not started formal Buteyko but have been nose breathing exclusively while consciously using less air. Haven't had to mouth breath since doing Viking Warrior Conditioning, everything I do now is within the template and guidelines of A+A and aerobic base building. Check out Al...

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[Kozushi]

Actually, mass times gravity is the static loading force, always pointing down.
mass times square of swing velocity divided by arm-bell lever is centrifugal force, always pointing along swing arm.

At bottom (probably fastest) position, they add up algebraically. A lazy swing will make the bell feel like 1.5 times its weight (1.5g).

S&S 2.0 book (p. 96) reports measured 10g swings with a 24K bell, making it feel like a static 240K weight!

Us mortals can probably muster 3-5g.

Those who do silly T-Rex swings stand to lose a lot of loading effect.

Not sure if the math works exponentially or not, but assuming not I'm calculating that if 10g swings with a 24kg bell make for 240kg virtual weight, that 10g swings with a 32kg bell make for 320kg of virtual weight and that 3g with the 32kg bell generates 96kg of virtual weight, so around 3 times the kettlebell's actual weight.

 

[Erik Hournou]

Actually, mass times gravity is the static loading force, always pointing down.

Gravity is acceleration.

 

[Erik Hournou]

185lbs is actually 84kg, so a bit under 3X the weight of the 32kg kettlebell we're swinging. But I do think the physical math gives us a pretty good if rough idea of how much heavier we're making the kettlebell by swinging it. Of course, at the top of the swing the virtual weight is reduced to less than the 32kg we started with! I wonder what it is up there? Maybe like 1kg, haha!

At the top the weight is exactly 0

 

[barrak]

Not sure if the math works exponentially or not, but assuming not I'm calculating that if 10g swings with a 24kg bell make for 240kg virtual weight, that 10g swings with a 32kg bell make for 320kg of virtual weight and that 3g with the 32kg bell generates 96kg of virtual weight, so around 3 times the kettlebell's actual weight.

1g = 9.8 m/s/s is acceleration of Earth's gravity
Additional g forces are proportional to square of swing speed. Assuming 1m arm-bell lever length, and
V = velocity of bell at bottom of swing
A = centripetal acceleration
xg = apparent weight (force) multiplier at bottom of swing

we get:

V (m/s) xg
---------------
3.1 2g
4.4 3g
5.4 4g
6.3 5g
8.8 9g

Here is an excellent scientific paper for this discussion:

Mechanical Demands of Kettlebell Swing Exercise : The Journal of Strength & Conditioning Research

xercise. Sixteen men performed 2 sets of 10 swings with 16, 24, and 32 kg, 2 back squats with 20, 40, 60, and 80% 1-repetition maximum (1RM), and 2 jump squats with 0, 20, 40, and 60% 1RM. Sagittal plane motion and ground reaction forces (GRFs) were recorded during swing performance, and GRFs...

journals.lww.com

The authors measured a consistent peak of 2,000 Newtons of force with a 24K kettlebell (Fig. 3 in the paper).
This translates to 2000/(24x9.8) = 8.5g which is equivalent to statically pulling 204Kg.

If the same kettlebell velocity is maintained with a 32K (which is a big if), then the same 8.5g applies and the static pull scales linearly to 272Kg.

 

[Erik Hournou]

@barrak thank you!

 

[LejonBrames]

@Kozushi, thank you for your awesome posts and observations on S&S lately. I absorbed a lot of wisdom from these posts.

 

[barrak]

@barrak thank you!

You're most welcome. Finally, my engineering degree is made useful to my kettlebell practice.

It's amazing how powerful the hip snap can be. Just consider the following quote from Pavel's Q&D + Minimalist Deadlifts | StrongFirst

I was watching Andy Bolton pull over 900 pounds from the back stage at the Arnold Classic. It struck me that his deadlift looked exactly like a hard style kettlebell swing. Afterwards, I asked Andy, “Correct me if I am wrong, it seems that you try to keep your shins vertical, don’t think about the leg drive, and snap your hips forward right from the start?” The man who would soon break the historic 1,000-pound barrier nodded, “Yes, you got it, that’s the way I pull. The hips go forward as soon as possible and as fast as possible and I don’t really think too much about the legs, they do their stuff without me thinking.”

 

[Bauer]

1g = 9.8 m/s/s is acceleration of Earth's gravity
Additional g forces are proportional to square of swing speed. Assuming 1m arm-bell lever length, and
V = velocity of bell at bottom of swing
A = centripetal acceleration
xg = apparent weight (force) multiplier at bottom of swing

we get:

V (m/s) xg
---------------
3.1 2g
4.4 3g
5.4 4g
6.3 5g
8.8 9g

Here is an excellent scientific paper for this discussion:

Mechanical Demands of Kettlebell Swing Exercise : The Journal of Strength & Conditioning Research

xercise. Sixteen men performed 2 sets of 10 swings with 16, 24, and 32 kg, 2 back squats with 20, 40, 60, and 80% 1-repetition maximum (1RM), and 2 jump squats with 0, 20, 40, and 60% 1RM. Sagittal plane motion and ground reaction forces (GRFs) were recorded during swing performance, and GRFs...

journals.lww.com

The authors measured a consistent peak of 2,000 Newtons of force with a 24K kettlebell (Fig. 3 in the paper).
This translates to 2000/(24x9.8) = 8.5g which is equivalent to statically pulling 204Kg.

If the same kettlebell velocity is maintained with a 32K (which is a big if), then the same 8.5g applies and the static pull scales linearly to 272Kg.

Interesting! So height and arm length play a role, too. For what it's worth the distance between my shoulder and my first is 60cm and the top and tge bottom ppsition of my swings are roughly 150 cm apart (straight line). Does this make a difference for calculations?

BTW, I have found that two-hand swings with a 32kg are more taxing my forearms than one-hand swings with a 16 kg.

 

[barrak]

Interesting! So height and arm length play a role, too. For what it's worth the distance between my shoulder and my first is 60cm and the top and tge bottom ppsition of my swings are roughly 150 cm apart (straight line). Does this make a difference for calculations?

BTW, I have found that two-hand swings with a 32kg are more taxing my forearms than one-hand swings with a 16 kg.

My math is way too simplistic as it assumes a fixed pivot point at the shoulder, so I wouldn't try to draw any variability conclusions. For example, it suggests at least 8 m/s bell velocity to reach 8.5g, whereas the paper measurements show 8.5g with peak bell velocity of 4.4 m/s..

In reality, the hardstyle swing involves two pivot points, both moving in space, at the shoulder and at the hip. (This would be an interesting advanced math problem for my overeager high schoolers. My 11th grade boy is currently taking Calculus II for Engineers at CU Boulder and is licking his college classmates so far.)

 

[Don Fairbanks]

My math is way too simplistic as it assumes a fixed pivot point at the shoulder, so I wouldn't try to draw any variability conclusions. For example, it suggests at least 8 m/s bell velocity to reach 8.5g, whereas the paper measurements show 8.5g with peak bell velocity of 4.4 m/s..

In reality, the hardstyle swing involves two pivot points, both moving in space, at the shoulder and at the hip. (This would be an interesting advanced math problem for my overeager high schoolers. My 11th grade boy is currently taking Calculus II for Engineers at CU Boulder and is licking his college classmates so far.)

Go Buffs.

 

[barrak]

Go Buffs.

Both his parents are CU Boulder alumni. Unfortunately, he's not terribly impressed with the lack of challenge from his classmates during Calculus I and II there. He's aiming high, at the likes of Stanford and Princeton.

My wallet shivers at my hip every time I think about it.

 

[Erik Hournou]

Both his parents are CU Boulder alumni. Unfortunately, he's not terribly impressed with the lack of challenge from his classmates during Calculus I and II there. He's aiming high, at the likes of Stanford and Princeton.

My wallet shivers at my hip every time I think about it.

Whatever you do, don't sell your kettlebells

 

[Kozushi]

Did some more thinking and calculating about the virtual weight of swings:

The carry over of regular S&S with the 32kg to deadlifting was being able to deadlift 320lbs with pretty much no training leading up to it. Heavier than that, no, it took training and patience. Of course deadlifting is not the same as swinging a kettlebell, but if the deadlift is the closest possible way to actually practically measure my "big pulling" strength that I got from kettlebell swings, then in my case the 32kg 100 reps 1 handed swings translated into 145kg (that's 320lbs) of deadlifting strength. I personally do not believe that I would have been able to deadlift that much weight without S&S behind me. I might have gotten in the mid 200s but not as high as 320lbs. So, I think, at least practically speaking, I have a kind of proof for how much virtual weight my 1h S&S swings are worth.

Not sure how scientific this is, but if we cut the 145kg in two based on the fact that I'm training my swings 1 handed, then my 32kg kettlebell swings are worth (only) 72.5kg. I don't doubt that the virtual weight at the bottom of my swings is much more than this, but in terms of transferring my kettlebell strength over to steady and continuous (real) weight, I'd thus postulate the actual practical "virtual weight" of my 32kg swings at 72.5kg. Thus the practical real world strength transfer of kettlebell swing training would be calculated as at 2.27 times the weight of the kettlebell.

I'm not so ignorant as to consider this "real" science. I can see LOTS of holes in the methodology here, but it could work as a sort of rough "working assumption" that shouldn't be extremely far off whatever the real answer is. ... this is only thinking of one handed work though.

In terms of 2 handed work, the 1 handed 32kg swings translated into a 145kg deadlift, making the 32kg kettlebell used 1 handedly for swings worth a deadlift 4.5 times(!) the weight of the kettlebell, so I'd postulate here that a 1 handed kettlebell swing is worth 4.5 times its own weight!!!

 

[Kozushi]

@Kozushi, thank you for your awesome posts and observations on S&S lately. I absorbed a lot of wisdom from these posts.

I'm curious. What kind of things especially?

 

[Nacho]

1. The Simple target with the 32kg bell is a target for a reason! If you are doing this regularly then you are VERY STRONG! The virtual weight of the 32kg bell is about 100kg! That means you're swinging your own bodyweight in just one arm! That's ridiculous! Going past Simple to 36kg or 40 or even 48 for some few blessed individuals is super impressive, but nobody should feel anything but exhilaration and pride at attaining and maintaining S&S with the 32kg bell! Simple is STRONG! With Simple I can do crazy things I could never handle before without hurting myself!

2. I finally broke down and purchased a "mid-way" bell (the 28kg) yesterday. I really liked my S&S workout with it today. It is obviously going to be smoother and easier if you progress by 4kg increments rather than by 8kg, and you might find your ultimate "maintenance weight" to be one of those increments (I might discover the 36kg for instance as my eventual "workhorse" S&S bell.) Nothing wrong with 4kg increments! This shouldn't be an issue. They're in the new S&S 2.0 book too!

I reached timeless simple maybe 8 months ago. I thought 32kg would be enough for me and I wouldnt go heavier. I had this 36kg bell lying around which I bought because I got a good deal even though it was way too heavy for me at the time. So now I started to consider selling it, but then I thought I might as well give it a try and see if I could slowly using it. So far so good, and I use it now for 40% of the sets and it feels moderately heavy but comfortable. 40kg would be a bit too much. 36kg is a nice little buffer to simple I think. Like a simple+. ?

 

[Kozushi]

I reached timeless simple maybe 8 months ago. I thought 32kg would be enough for me and I wouldnt go heavier. I had this 36kg bell lying around which I bought because I got a good deal even though it was way too heavy for me at the time. So now I started to consider selling it, but then I thought I might as well give it a try and see if I could slowly using it. So far so good, and I use it now for 40% of the sets and it feels moderately heavy but comfortable. 40kg would be a bit too much. 36kg is a nice little buffer to simple I think. Like a simple+. ?

Yeah, we all hit a different "sweet spot" with weights. I also think this sweet spot changes over time, which is why we need several different weights. Also, we need heavy and light and even medium days. It's worth it having several different bells. My next purchase is going to be a 36kg.

 

[mar2safety]

I reached timeless simple maybe 8 months ago. I thought 32kg would be enough for me and I wouldnt go heavier. I had this 36kg bell lying around which I bought because I got a good deal even though it was way too heavy for me at the time. So now I started to consider selling it, but then I thought I might as well give it a try and see if I could slowly using it. So far so good, and I use it now for 40% of the sets and it feels moderately heavy but comfortable. 40kg would be a bit too much. 36kg is a nice little buffer to simple I think. Like a simple+. ?

Yeah, we all hit a different "sweet spot" with weights. I also think this sweet spot changes over time, which is why we need several different weights. Also, we need heavy and light and even medium days. It's worth it having several different bells. My next purchase is going to be a 36kg.

I bought my 36 in May/June after hitting simple timeless for a few weeks in a row. I started progressing 2HS separate from 1HS, so the 36 is now my 2HS weight, has been since the summer. I haven't swung it 1 handed yet, but I'm already looking at 40 to progress further.

 

[NormanOsborn]

Timeless Simple is 10 x 10 one handed Swings, and 2 x 5 TGU's, both with the 32kg, yeah?