Defining, Testing & Categorizing Jumps / Plyometrics
In almost every athletic development program you will find jumping/plyometrics included. There are various performance and injury reduction benefits to implementing jumps/plyometrics into an athlete’s program, but like with any other training quality the timing and type of variation you do is specific to each athlete's needs. For some, addressing single effort jumps might be the best variation, while for others it might be reactive jumps. In this article we will define terms associated with jumping/plyometric training, give examples of how to evaluate an athlete's jumping ability on a budget and explain how we categorize our jumps/plyometrics at EForce.
Defining Jumps/Plyometric Terminology
Over the course of the last decade Sports Performance Coaches have gone back and forth in regard to the nuanced differences in defining “Jumps” and “Plyometrics.” These include statements like “all jumps are plyometrics, but not all plyometrics are jumps” or “I see them as the same thing, but it depends on whom you talk to.” While I acknowledge that there is an argument that they are similar but different, for simplicity's sake we will consider them one-in-the-same.
Jump/Plyometric Training:
Originally known as the ‘’Shock-method,’’ the term plyometrics was proposed by North American track coach Fred Wilt. Plyometrics are defined as quick powerful movements that utilize the stretch-shortening cycle (SSC) and are aimed at developing speed-strength and explosiveness.
Stretch-Shortening Cycle:
The SSC is rapid muscle lengthening followed by rapid muscle shortening that works to optimize the stretch reflex and stored elastic energy.
Jump Variations:
Any drill that is a two-foot take-off followed by a two-foot landing.
Hop Variations:
Any drill that is a single foot take-off followed by the same single foot landing.
Bound Variations:
Any drill that is a single foot take-off followed by the opposite single foot landing.
Evaluating An Athlete’s Jumping Ability (EUR)
There are a lot of different ways to assess an athlete’s jumping abilities. These assessments can include using equipment such as; jump mats, force plates, video analysis, etc. Unfortunately, not everyone has access to these types of equipment, but that doesn’t mean you can’t assess an athlete's jumping ability. One cheap and effective way is looking at an athlete’s Eccentric Utilization Ratio (EUR).
Eccentric Utilization Ratio (EUR):
The EUR evaluates the ratio between an athlete’s Countermovement Vertical Jump and Non-Countermovement Vertical Jump. This test can provide insight on how well an athlete leverages their SSC and stored elastic energy; invertibility helping a coach determine where an athlete falls on the spectrum of power vs elastic dominance. Research suggests that when athletes are able to leverage their SSC their CM Vertical Jump should be roughly 10% greater than their NCM Vertical Jump, or an EUR of ~1.10.
EUR Testing Procedure:
To test an athlete's Eccentric Utilization Ratio follow the steps below:
- Have the athlete perform your preferred dynamic warm-up.
- Have the athlete perform 2 NCM Vertical Jumps with their hand on their hips and allow for adequate rest (full recovery) between attempts.
- Have the athlete perform 2 CM Vertical Jumps with their hand on their hips and allow for adequate rest (full recovery) between attempts.
- Finally, take the athletes best CM Vertical Jump and divide it by their best NCM Vertical Jump (CM Vert / NCM Vert = EUR)
Example: CM Vert (28in) / NCM Vert (26in) = 1.08
EForce’s 4 Categories For Jumps/Plyometrics
As with many things, having systems of organization and categorization can drastically help with the decision-making process. At EForce, once we’ve determined an athlete’s jumping abilities through our EForce Jump Profile, along with taking into account the other information we get from our evaluation we can start to pick the appropriate jumps to add to an athlete’s program. Below are the 4 Categories we use:
For those new to coaching/training or that are looking to quantify and systematize their jumps/plyometrics we hope that the above information can provide a framework to do so. Since refining our testing/categorization for jumps/plyometrics we’ve seen more consistent and greater predictable results for our athletes at EForce.
If you’re an athlete looking to elevate your speed, power and strength… look no further than EForce Performance!!
Erik Jernstrom
Director of Sports Performance @ EForce
