See how he gets his ass down under the bar (without popping the bar up first).
Does he descend faster than gravity causes the bar to fall…
Or does his extending his arms cause the bar to descend slower than gravity would cause it to fall.
?
Now…
Lets imagine more weight on the bar.
Does something magically specially different happen when he is the same weight as the bar?
How about when the bar is heavier than him?
?
(I suppose you could record it and see… But shouldn’t you be able to figure it out from physics. Someone… Who knows physics… Someone?)
[quote]alexus wrote:
I have a question that has been bugging me for YEARS now.
I’m interested in this particular exercise:
See how he gets his ass down under the bar (without popping the bar up first).
Does he descend faster than gravity causes the bar to fall…
Or does his extending his arms cause the bar to descend slower than gravity would cause it to fall.
?
Now…
Lets imagine more weight on the bar.
Does something magically specially different happen when he is the same weight as the bar?
How about when the bar is heavier than him?
?
(I suppose you could record it and see… But shouldn’t you be able to figure it out from physics. Someone… Who knows physics… Someone?)[/quote]
I’m reading it as a combination of both. Extending his arms causes the bar to descend slower (or ideally the bar will descend at zero speed, i.e. not change position at all). By Newton’s third law, since he’s pushing up against the bar he’s also pushing himself downwards. This force combined with gravity means he’ll drop faster than if he were to do it without the bar.
With more weight on the bar I expect he’ll move faster as he exerts more force against the bar to keep it fixed in space. Once he’s past the maximum amount he can press then he’ll still drop just as fast, but then have the bar slowly drop down onto his shoulders.
Now to chuck a wrench into the mix: He may also slow his own descent by pushing with his legs, and I’m pretty sure he’s doing so in the video.
[quote]238 wrote:
I’m reading it as a combination of both. Extending his arms causes the bar to descend slower (or ideally the bar will descend at zero speed, i.e. not change position at all). By Newton’s third law, since he’s pushing up against the bar he’s also pushing himself downwards. This force combined with gravity means he’ll drop faster than if he were to do it without the bar.
With more weight on the bar I expect he’ll move faster as he exerts more force against the bar to keep it fixed in space. Once he’s past the maximum amount he can press then he’ll still drop just as fast, but then have the bar slowly drop down onto his shoulders.
Now to chuck a wrench into the mix: He may also slow his own descent by pushing with his legs, and I’m pretty sure he’s doing so in the video.[/quote]
Thanks for the discussion.
I guess the way to think of it is like the cases where someone is free-falling (feet pointed towards earth) and then their lift their arms up. When this happens… Do their arms slow down (relative to the earth) or does their body speed up or both? Arms slow down, yeah? Bar slows down or its position is unchanging.
Part of this is because it is meant to be common wisdom that ‘the descent under the bar for the snatch is the fastest movement in sport’ because the lifter ‘descends faster than the speed of gravity’ but… Uh… if the lifter is slowing the descent of the bar then the lifter doesn’t need to descend faster than the speed of gravity to get their ass under it…
So maybe it is bollocks.
I wish I had one of those cameras that could tell me the speed of the bar because then I could see how it fares in relation to freefall…
[quote]tork94 wrote:
dont do it. the drop-snatch is imo one of the most useless exercises ever[/quote]
Well, I’ve seen the drop snatch in a lot of elite-level lifter’s programs, so it can’t be that bad. A junior European champ from Romania has stated that they worked the drop snatch to about 110-120% of best snatch. This is a guy that went 170/200 as a 94kg junior!!
[quote]alexus wrote:
Part of this is because it is meant to be common wisdom that ‘the descent under the bar for the snatch is the fastest movement in sport’ because the lifter ‘descends faster than the speed of gravity’ but… Uh… if the lifter is slowing the descent of the bar then the lifter doesn’t need to descend faster than the speed of gravity to get their ass under it…
So maybe it is bollocks.
[/quote]
A good lifter will descend faster than a similar object that is free falling (gravity doesn’t have a speed, it’s a force that applies a constant acceleration) because they continue pulling on the bar until they are underneath it. In that split second when the lifter’s feet are off the ground, they are no longer exerting any upward force on themselves or the barbell but are continuing to pull as hard as they can which translates to a downward force on the body relative to the barbell. Ideally this is happening as the barbell reaches its maximum height, so that the lifter is already underneath the bar before it begins to fall again. Which is why some coaches are adamantly against pulling for too long, as then you aren’t pulling yourself under the bar until it has already started coming back down at which point it simply becomes a race between you and the bar as to who can hit the bottom position first, and it’s much harder to pull yourself under a falling object than it is an object that is still rising. This is where timing can come into play.
This may also be why tork is against drop snatches (and why I may agree with him, despite having done them in the past). Speed under the bar doesn’t come from dropping as fast as possible, it comes from actively pulling on the bar, and you don’t get that doing a drop snatch. One could make the argument that the exercise helps reinforce stability in the bottom position of the snatch, which I guess it does, but if that’s the goal you’re probably better off doing a snatch balance (more of a behind the neck snatch grip push jerk that you ride down into a full overhead squat) as you can use heavier loads. Maybe it could be helpful in teaching someone to relax their legs as they’re descending under the bar, but practicing that without simultaneously practicing the timing of that relaxation that comes with the reversal of the body’s momentum when performing a regular snatch is of minimal utility, I’d say.
As a final note, I know someone who tells people he’s teaching the lifts to that they need to “be fast.” I disagree with this. I am more a proponent of “smooth is fast” and “be quick, but never in a hurry” (and those are applicable to other athletic pursuits as well). Speed will come if you do the lift properly, hitting the correct positions and continuing to pull all the way into the rack position. If you try to “be fast” you are much more likely to fuck something up.
Speaking of fucking things up, hopefully that rant makes sense.
Makes a lot of sense, Jonty!! And I meant snatch balance in my post right above yours. I always thought the two were interchangeable, just using different terms for the same exercise.
[quote]tork94 wrote:
dont do it. the drop-snatch is imo one of the most useless exercises ever[/quote]
Well, I’ve seen the drop snatch in a lot of elite-level lifter’s programs, so it can’t be that bad. A junior European champ from Romania has stated that they worked the drop snatch to about 110-120% of best snatch. This is a guy that went 170/200 as a 94kg junior!![/quote]
Are you sure they weren’t snatch balances? Like this?
The differences between the video in the OP and this one should be self-evident, and I’ve seen confusion in the past over which is called which. Semantics, really.
A good lifter will descend faster than a similar object that is free falling (gravity doesn’t have a speed, it’s a force that applies a constant acceleration) because they continue pulling on the bar until they are underneath it.
wouldn’t this only apply when the bar is heavier than them?
Which is why some coaches are adamantly against pulling for too long, as then you aren’t pulling yourself under the bar until it has already started coming back down at which point it simply becomes a race between you and the bar as to who can hit the bottom position first, and it’s much harder to pull yourself under a falling object than it is an object that is still rising. This is where timing can come into play.
Yes. That does make sense. I usually fail on snatches because I don’t pull it sufficiently high (a little forwards and short). But I do get what you mean on timing it so the bar doesn’t even fall at all (when the weights are light, anyway).
Speed under the bar doesn’t come from dropping as fast as possible, it comes from actively pulling on the bar, and you don’t get that doing a drop snatch. One could make the argument that the exercise helps reinforce stability in the bottom position of the snatch, which I guess it does, but if that’s the goal you’re probably better off doing a snatch balance (more of a behind the neck snatch grip push jerk that you ride down into a full overhead squat) as you can use heavier loads. Maybe it could be helpful in teaching someone to relax their legs as they’re descending under the bar, but practicing that without simultaneously practicing the timing of that relaxation that comes with the reversal of the body’s momentum when performing a regular snatch is of minimal utility, I’d say.
I do them because (unlike most people) I need to bounce out the bottom of my snatches or I get stuck in the hole. So I practice dropping into bottom position and bouncing straight out. Helps me aim my catch, if that makes any sense. But I’m a freak…
As a final note, I know someone who tells people he’s teaching the lifts to that they need to “be fast.” I disagree with this. I am more a proponent of “smooth is fast” and “be quick, but never in a hurry” (and those are applicable to other athletic pursuits as well). Speed will come if you do the lift properly, hitting the correct positions and continuing to pull all the way into the rack position. If you try to “be fast” you are much more likely to fuck something up.
I’ve been doing some boxercise weirdness (long story). The guy who took the class was very good. Trained as a ballet dancer, apparently. He managed to teach me… That relaxed is faster. We did a lot of punching / kicking combos (to music ha!) that were very fast… One needed a certain amount of relaxation to get the speed out. I think this translates.
Any added downward force will cause you to accelerate downward faster. Your mass is constant and Force = mass x acceleration. You won’t get much downward force from pulling a light bar and will therefore not drop as fast as you can when pulling a heavier bar, but the bar’s weight in relation to your own is irrelevant. My opinion is that it is easier to approach understanding force and acceleration in weight lifting intuitively rather than using physics if you are not a physics buff. You know from experience that when you pull a light bar it doesn’t push you to the ground as hard as when you pull a really heavy one.
[quote]thegymismyshrink wrote:
You know from experience that when you pull a light bar it doesn’t push you to the ground as hard as when you pull a really heavy one. [/quote]
I don’t know that from experience. That is why I have been wondering about the physics…
I suspect I’m consistently not finishing my pull… I will try and envisage continuing the pull through for my descent instead of thinking of it as a drive then drop then bounce.
