Sunday, April 8, 2007
Rips reply to vertical question
It's nice to have the author of what I'm going to call my current strength bible answer my question, crossfit is such a cool community!
"It has been my experience, and the observation of most experienced coaches, that a trained vertical jump does not improve much over the course of an athlete's career. My guess is that it might improve 20-25%, but certainly not as much as other aspects of performance. Some initial progress is inherent in learning how to effectively do the test, but after that the limitations imposed by inherited neuromuscular efficiency tend to limit vertical jump progress. For this reason, it is a good indicator of talent for explosive athletics in younger kids, since the capacity is present from birth and expresses itself early. It is one of the more useful components of the NFL combine tests because it reveals potential, as well as current ability, which the squat might not do. Strength, technique, and psychological ability can make huge improvements, but only within the context of genetically-constrained neuromuscular efficiency.
Actually, this points out the primary flaw in the CFN tables, especially if they are presented as a progression. Performances that are heavily dependent on neuromuscular system factors and the endocrine/neural components that control them are subject to the limitations thereof. Individual genetics, male/female differences in potential, and age-specific factors must all be considered in the development of any table of performance standards. It appears as though the CFN tables suggest that it is possible to improve one's vertical jump from 10" to 30", and this is simply not possible. And there are no differences in standards for the "military press" between male and female, or for most of the other tests that most definitely display different potentials respective of sex - the reason competitive sports have men's and women's divisions.
In addition, performance in strength-dependent tests does not vary with bodyweight in a linear manner; performance suffers relative to bodyweight among taller, heavier athletes. This fact is reflected in the "best lifter" formulas used in both powerlifting and weightlifting, and has been recognized for many years as necessary to take into account when comparing the performances of different athletes. The CFN tables do not allow for this commonly observed phenomenon." - Mark Rippetoe