Physics puzzle: chin-ups.

[pzhon]

Suppose I weigh 200 pounds and can perform a set of 10 chin-ups. What weight of dumbell should you expect me to be able to curl 10 times?

[billygrippo]

well these are not all the same musscles at work here.

[pzhon]

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well these are not all the same musscles at work here.

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Right, not all are the same. The chin-up uses back muscles, too. What component of the chin-up comes from using the muscles involved in a curl?

[billygrippo]

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well these are not all the same musscles at work here.

[/ QUOTE ]
Right, not all are the same. The chin-up uses back muscles, too. What component of the chin-up comes from using the muscles involved in a curl?

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i have no idea.

this is more of a personal trainer question than a physics one.

[pzhon]

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i have no idea.


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So why post?

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this is more of a personal trainer question than a physics one.

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It is a physics problem with applications to other areas. While I might get better feedback by asking experienced physical trainers, this has applications to bar bets, too. If you see that someone can't quite curl 75 pounds, is it safe to bet that he can't do a 1-handed chin-up?

[billygrippo]

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If you see that someone can't quite curl 75 pounds, is it safe to bet that he can't do a 1-handed chin-up?

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i would say no, and 1 handed chin ups are absurdly hard.

[evolvedForm]

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If you see that someone can't quite curl 75 pounds, is it safe to bet that he can't do a 1-handed chin-up?

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Nope. I can do a one handed chin-up, but I'm not even close to curling 75 pounds (with one hand at least). More like 50 for a 1-rep max when I'm in good shape.

As for your problem, it seems impossible to measure accurately. There are too many factors, one of which is how proficient the individual lifter is at the chin-up versus the curl. This fact throws off your whole study, since it is dependent on the subject. You might be able to figure out some reasonable range, however. To do that would probably take experiments, though. This cannot be determined conceptually.

[mostsmooth]

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[ QUOTE ]
well these are not all the same musscles at work here.

[/ QUOTE ]
Right, not all are the same. The chin-up uses back muscles, too. What component of the chin-up comes from using the muscles involved in a curl?

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underhand chinups, as in your palms would be facing you.

[Central Limit]

people who are very thin can often do many chin-ups but not curl very much.

[billygrippo]

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people who are very thin can often do many chin-ups but not curl very much.

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youre a genius.