❗ Controversial opinion ❗ Look at fewer, simpler metrics on your...
Eamonn Flanagan@EamonnFlanagan
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Oct 13, 2025
~2 min read
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❗ Controversial opinion ❗
Look at fewer, simpler metrics on your force plate CMJ but increase your variety of jump tests utilised
Trend seems to be to look at myriad of physical qualities from CMJ: eccentric strength, concentric RFD, reactive strength. List is endless...
Look at fewer, simpler metrics on your force plate CMJ but increase your variety of jump tests utilised
Trend seems to be to look at myriad of physical qualities from CMJ: eccentric strength, concentric RFD, reactive strength. List is endless...
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However many of these physical parameters are constrained by the test/exercise itself
Yes, you can look at eccentric RFD in a CMJ but the relative loading of these ecc. strength qualities will always be somewhat "under loaded" in this test
Yes, you can look at eccentric RFD in a CMJ but the relative loading of these ecc. strength qualities will always be somewhat "under loaded" in this test
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The degree of eccentric loading will be constrained by the jumping strategy of the athlete and by the nature of the CMJ task itself.... There just isn't that much eccentric loading (relative to high eccentric demand sporting tasks) in a CMJ
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Its attractive to think that we can look at everything in a single test. Are we kidding ourselves?
If you want to track a specific quality, use a test that overloads it
Ecc impulse/RFD = DJ
Con impulse/RFD = SJ
Cyclical reactive strength = 10-5 RJT
Symmetry = single leg jumps
If you want to track a specific quality, use a test that overloads it
Ecc impulse/RFD = DJ
Con impulse/RFD = SJ
Cyclical reactive strength = 10-5 RJT
Symmetry = single leg jumps
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The beauty? When the test is "specific" we can look at simpler metrics.
If your jump height is increasing in a DJ (from fixed height) - your eccentric qualities are highly likely improving. Do you really need to drill into countless eccentric force related metrics?
If your jump height is increasing in a DJ (from fixed height) - your eccentric qualities are highly likely improving. Do you really need to drill into countless eccentric force related metrics?
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If your jump height in a squat jump is increasing, your concentric strength is improving. If your contraction time drops and jump stays in same ballpark? Your RFD qualities are highly likely improving.
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Solution? Rapid fire jump testing.
Rattle through a 3-4 jump protocol in <4 mins. Each jump seeks to answer a specific question or represent a specific quality. Order jump types by priority/relevance (most important first)
Example:
SJ x 2
CMJ x 2
Single leg CMJ x 2 R&L
10-5 RJT
Rattle through a 3-4 jump protocol in <4 mins. Each jump seeks to answer a specific question or represent a specific quality. Order jump types by priority/relevance (most important first)
Example:
SJ x 2
CMJ x 2
Single leg CMJ x 2 R&L
10-5 RJT
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Analysis can be super simple: you're gaining specificity w/ jump types so you can be general w/ metrics = jump height, contact/contraction time, ratios.
Sub-optimal recovery between tests isn't ideal but can be managed if you standardise warm-up & order every testing day
Sub-optimal recovery between tests isn't ideal but can be managed if you standardise warm-up & order every testing day
