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Isometric vs. Concentric Strength

Looking for a little homework help… I need a reference comparing isometric force production to concentric force production. I thought there was something about isometric vs eccentric vs concentric in “Science and Practice of Strength Training” but can’t find what I need.

It gets mentioned here all the time, so I was wondering if anyone would know a reference that would be easy to get. Even an online journal article would work…

Reference - Essentials of Strength and Training and Conditioning page 41.

In a nutshell, Eccentric can produce the greatest force because it is easy. Isometric is next and then concentric produces the least amount of force.

Easy real life example to get the point is imagine you are doing push-ups. Generally once you no longer have the strength to do a push-up (concentric) you could still hold yourself in position for a little while (isometric) and when you no longer have the strength to do that then you can still lower yourself down to the ground with some control (eccentric).

Regular strength training tends to bring concentric levels up closer to eccentric and isometric levels so there is not as big of a difference with trained people as there is with untrained people.

Hope that was what you were looking for.

Isometric, concentric and eccentric used together (a.k.a regular weight lifting) have been show to provide the greatest improvements in strength and power saids Mell Siff (supertraining)

Thanks, I’ll probably use the NSCA book (essentials of s&c). Were there any numbers included with it, like ratios of eccentric vs concentric strength abilities?

There are charts on the previous page that have some ratios. Then on page 10 they say:

“The force capabilities are typically 120-160% greater in eccentric actions than concentric actions” which is referenced.