Taller lifter stronger?

[PrimalFish]

Hello Mark,

Does a taller lifter produce more force then a shorter lifter to move the same weight in the squat?

Hypothetically, say there existed a 10 foot tall man and a 5 foot tall man who had the exact same anthropometry and levers. They both squat with the exact same perfect form and to have the same rep maxes. Is the taller lifter stronger? In this example, would he be twice as strong? If he is not stronger, could you explain what differences there would be, if any?

Thank you.

[Mark Rippetoe]

You are using the terms incorrectly. Strength is the production of force against an external resistance. A man who lifts 405 off the floor has to exert "406" pounds of force to move it up. If he exerts 455, it moves faster. If he exerts 405, it stays where it is. Doesn't matter how tall he is.

[This Old Man]

The taller lifter does more work. In the physics sense, work is force times distance. As the Coach points out both lifters must exert the same force to lift the same weight, but the taller one moves it farther, thus doing more work.

[shib]

Hello Mark,

Does a taller lifter produce more force then a shorter lifter to move the same weight in the squat?

Hypothetically, say there existed a 10 foot tall man and a 5 foot tall man who had the exact same anthropometry and levers. They both squat with the exact same perfect form and to have the same rep maxes. Is the taller lifter stronger? In this example, would he be twice as strong? If he is not stronger, could you explain what differences there would be, if any?

Thank you.

The term I think you might be reaching for is work not strength.

If you consider the distance the barbell needs to travel in both men, the 10 foot man must move the bar over a much longer range than the 5 foot man. The force required the displace the bar vertically against gravity is the same in both cases, but the taller lifter has to do much more work (work = Force * Displacement * cos(theta)) to complete the movement.

So in your instance the 10 foot might have a greater work capacity but is not necessarily stronger.

[PrimalFish]

You are using the terms incorrectly. Strength is the production of force against an external resistance. A man who lifts 405 off the floor has to exert "406" pounds of force to move it up. If he exerts 455, it moves faster. If he exerts 405, it stays where it is. Doesn't matter how tall he is.

This makes sense. Thanks.

The term I think you might be reaching for is work not strength.

If you consider the distance the barbell needs to travel in both men, the 10 foot man must move the bar over a much longer range than the 5 foot man. The force required the displace the bar vertically against gravity is the same in both cases, but the taller lifter has to do much more work (work = Force * Displacement * cos(theta)) to complete the movement.

So in your instance the 10 foot might have a greater work capacity but is not necessarily stronger.

So I guess one could say that the 10 foot man does twice as much "work" or has double the "work capacity" as the 5 foot man.

What does it mean to have a better work capacity though? Does the 10 foot man have more endurance? Power? Muscle? What does the 10 foot man have over the 5 foot man that allows him to have twice the work capacity? Is this some aspect of strength?

[Mark Rippetoe]

What does the 10 foot man have over the 5 foot man that allows him to have twice the work capacity? Is this some aspect of strength?

Very bad genetics, and necessity. Once again, strength is the production of force against an external resistance. That is all it is.

[spacediver]

What does it mean to have a better work capacity though? Does the 10 foot man have more endurance? Power? Muscle? What does the 10 foot man have over the 5 foot man that allows him to have twice the work capacity? Is this some aspect of strength?

Someone correct me if I'm making a thinking error:

Remember, strength here is defined as the force applied to the barbell.

The taller man will have greater limb lengths, and his muscles will therefore have to produce more force, resulting in greater torque, but the end result will be that the barbell experiences the same applied force.

So if we define strength on a reductionist level (e.g. suppose we could measure the force applied to an individual joint by an individual muscle group), the taller man will be stronger.

But if we define strength on a practically applied level (e.g. how much force can be applied to the barbell), both men are equally strong.

This is a point that is often lost in discussion, and I think it's an important clarification.

The reason that the taller man does more work per rep (note, this is different from having a higher work capacity: the shorter man may be able to do twice as many reps as the taller man, resulting in the same amount of work done), is that in one rep, the barbell experiences more displacement than with the shorter man.

[Mark Rippetoe]

Remember, strength here is defined as the force applied to the barbell.

The taller man will have greater limb lengths, and his muscles will therefore have to produce more force, resulting in greater torque, but the end result will be that the barbell experiences the same applied force.

So if we define strength on a reductionist level (e.g. suppose we could measure the force applied to an individual joint by an individual muscle group), the taller man will be stronger.

The bar weighs 405. Strength is force production against an external resistance. So, what are you talking about?

[spacediver]

The bar weighs 405. Strength is force production against an external resistance. So, what are you talking about?

If strength is defined that way (and I have no issue with that definition), then the two lifters are equally strong. The point I was making is aimed at deconfusing those who equate strength with the force production capabilities of individual muscles.

[Tiedemies]

The bar weighs 405. Strength is force production against an external resistance. So, what are you talking about?

I think he was differentiating the force produced by the muscle on the insertion point (I suggest we call this "internal force production") and the force acting on an external object, i. e., strength.

I believe the point he made was that the muscles of the larger man who is equally strong and with equivalent anthropomery, must produce more internal force due to the longer leverages.

This seems plausible. The moment arms from the points of support and so forth will be longer in the larger man. This would in all likelihood be visible in the larger man having, again all other things like neuromuscular efficiency being equal, larger cross-section in his muscles.

I don't know that this has any relevance whatsoever to much anything. Perhaps if you were able to do some weird muscle transplants or something, you would have better material from the larger man. But that even seems implausible as the muscles would be longer and thus not comparable.