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Normally when people going to the gym and want to make "bench press" exercise using a bar with weight plates, the order of the plates (on both sides of the bar) is from the heaviest (internal) to the lighter (external). For example:

normal order: 20 kg > 10 kg > 5kg

Then my question now, if there is a difference physically (both: definition No.4 and definition No.1) in case of changing the order (reorder / reorganize) on both sides of the bar - the same. For example:

order No. 1- from inner to the outer: 5 kg > 10kg > 20kg

another example:

order No.2- from the inner to outer: 20 kg > 5kg > 10kg

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Ubiquitous Student
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3 Answers3

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Regarding bar deformation:

Bars do bend, and specialized deadlift and olympic lifting bars are designed to bend significantly when they are lifted. This is referred to as "whip" and allows the lifter to "take out slack" on the bar. This has two primary effects on deadlift, or lifts done off of the floor:

  1. The natural flexibility built into these bars allows the lifter to take more time to achieve an output force equal to the weight they are trying to lift. This is physiologically important because there are reflexes that inhibit force production. These reflexes are triggered by the deformation of tendons, and tendons deform more when the rate of change of force (jerk) on the external object is greater because in addition to the force of raising the weight (mg), the lifter must accelerate the mass of the "weight" (ma) and the acceleration on the center of mass is decreased if the bar allows the lifter to take out slack. This means that the lifter may be able to achieve the force needed to get the bar off the ground without having his or her tendons stretch to a point that will cause an inhibitory signal.

  2. Taking out slack raises the center of mass of the "weight" without requiring the lifter to exert enough force to break contact with the ground. It also lowers the center of mass relative to the lifter's hands. This means that the lifter will not have to raise the center of mass by as great a distance to complete the lift. It also means that the lifter will not have to exert enough force to equal the weight of the bar until they are in what is usually a better bio-mechanical position to exert force.

In both of these cases, a and b, loading the bar small to large will increase the degree of deformation that these specialized bars will experience, furthermore, loading a high whip bar with more weight further out can have a significant affect on how hard it is to lift the bar. There will be a similar but smaller effect on more rigid bars.

rob
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Joseph Hirsch
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If the maximum weight is placed further away from where your hands are, it causes more bending of the bar, potentially overcoming its elasticity limit. If it happens, the bar might not recover its initial straight shape, and (rarely) suffer some imperceptible damage.

fffred
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  • But when talking about the gym's bar then the strength of the bar is constant for the weight plates. they does not change the bar form / shape. – Ubiquitous Student Nov 26 '16 at 13:48
  • I don't understand your comment. The bar does not deform when you put more weight ? If you hold the bar only from the middle and you put a lot of weight on each side, it will bend, and even break at some point. Every bar has a limit on the load it can carry before breaking. – fffred Nov 26 '16 at 14:01
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    Of course, but obviously I'm talking about using in the limit rather than outside the limit (the bars at gym which are designate for bench press, normally can carry heavy weight - 1000lb...). So outside of this limit is not relevant for gym, that why it was unnecessary to mention in the post. – Ubiquitous Student Nov 26 '16 at 14:12
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    @Industrious : I agree. They gym is not going to use a bar which will bend or break significantly when you use it. I agree with Kyle Kanos : the only significant difference is that having the heavier weights nearer the centre makes it easier to keep the bar from tilting further if it is not quite horizontal. – sammy gerbil Nov 26 '16 at 15:28
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It will definitely make a difference, and reason I know is because I’ve tried it, which is what I suggest if you really want to know the answer. The farther away the heavier plates are, the greater the gravitational pull will be, thats as scientific as l get.

CT Fletcher
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