For every fallacy that exists at the high school level of strength and conditioning, there is one equal to or greater than at the collegiate level.  I have personally witnessed Division 1 S&C coaches build a team’s program around the needs of a handful of starting players.  I’ve witnessed coaches test athletes in April and base June’s program solely off of April’s tests.  And worst of all, I’ve seen more forced reps than I care to admit.  All the while, putting the athletes at risk for injury and avoiding any adaptation of strength and power.

I will admit, programming for a large team is not easy.  How is a coach expected to build an optimal program for a large team when nearly every player has different strength and weaknesses and an end goal is not weight room performance but on the court/field success?  I’m going to provide you with a valuable assessment tool to utilize in the development and testing phases of your athletes: the vertical jump.

Although used as a fundamental benchmark by highest level of professional sports, the vertical jump is a very underutilized assessment tool for subsequent levels.  The coaches and scouts at the NFL and NBA combines are searching for dynamic athletes that can demonstrate lower body strength and explosiveness as it relates to horizontal and vertical displacement.  This view works for that level because those coaches are looking for developed athletes, not athletes they need to BE developed (professional sports has very little time to develop athletes).  With this in mind, should strength coaches at the developmental levels be looking at vertical with the same perspective as an NFL scout?

No and here’s why; the vertical can be a window for a coach to see an athlete’s training experience and limiting factors of strength, power or central nervous efficiency that may be affecting that individual’s performance. This article will outline the specific assessment components of the vertical jump to show you, the coach or the athlete, the specific training approach to improve the universal biomarkers of performance.

The Vertical Jump Performance Window

Many strength coaches make the common mistake of focusing on a single element in hopes of increasing an athlete’s vertical jump and performance.  This element always results is more strength training.  But what training adaptation in particular is responsible for increasing vertical jump and/or performance?

Is it only strength?  Strength is a broad term, which unfortunately, is often simply viewed linearly as an increase is weight on a barbell.  With this POV, let’s use a classic Zatsiorsky example of increasing strength and applying it to the vertical jump.

“A young athlete began to exercise with free weights, performing squats with a heavy barbell equal to his body weight (BW).  His performance in a standing vertical jump was 40cm.  After 2 years, his achievement in the barbell squats was 2-BW, and the vertical jump increased to 60cm. He continued to train in the same manner and after 2 years was a able to squat 3-BW.  However, his jump performance was not improved because the short takeoff time rather than maximal absolute force became the limiting factor.” (3)

Increasing strength can improve an athlete’s vertical jump, but not forever. Eventually, a new stimulus is needed for that athlete to continue to progress, and that stimulus isn’t more weight on the bar.  This is called the Law of Accommodation.  Relying solely on heavy weight training to increase VJ has not been found to adequately enhance specific components of explosive movements such as rapid excitation of muscles and the rapid changing from eccentric to concentric work. (2)  If you continue to increase strength linearly but execute the movement slowly, the muscles begin to ‘learn’ slowness and there will be a decrease in the power exhibited (1).

So we need to focus on Power, right?

Strength is a vital component of athleticism, but it sits stranded on an island WITHOUT power.  Power is defined as an athlete’s ability to dynamically display their strength and the rate this can be displayed at any instant.  The ability to increase power or explosiveness depends on specifically training the Rate of Force Development (RFD) (2).  The RFD is the rate at which the required maximum force is developed, and is an important element for resolving the task of special strength training, which relates directly to the neuromuscular system (2).

Ok, so now the Central Nervous System?

One of the central features of all motor skill is the ability to produce maximal power and power in the most efficient manner possible.  Force development is greatest with an athlete who has a highly adapted and trained central nervous system.  A group of muscles ability to produce force is proportionate not only to muscle size but also to the number and efficiency of the appropriate muscle fibers firing.  We have seen mental factors and technical expertise are often neglected in this training at the developmental levels. But no athlete should ever focus largely on these at the expense of practice firing and using muscles as they would in their sport (2).

But the age-old question still remains, is your vertical jump increased by increasing strength?
Yes.

By increasing power?
Yes.

Does increasing Central Nervous System efficiency help?
Yes.

Relying on just focusing training one element, while neglecting the others, will prevent the full development of an athlete’s strength, power or CNS efficiency.  This understanding is vital when analyzing the design of strength training program with the hopes of improving athletic performance.  One must understand if an athlete is severely lacking in one, their limiting factor becomes the weak link that shows up on Game Day.

This leads us to the assessment tool, which identifies exactly which of these your athletes needs to focus on to improve performance.

Explosive Strength Deficit

Here we introduce the concept of assessing the Explosive Strength Deficit using the vertical jump to measure explosive strength and determine what specific type of training the athletes will need.  Zatsiorsky defines explosive strength as the ability to exert maximal forces in minimal times (3), crucial for success on the field. Strength deficit is the difference between maximum strength (voluntary effort) and absolute strength (involuntary effort) of which the athlete is capable during a movement (2).

The Explosive Strength Deficit assessment compares two jumps to show the approximate strength potential the athlete is not able to generate and helps estimate an athletes Rate of Force Development. RFD can be seen naturally as athletes progress through levels of their sport. Example: A linebacker progresses through high school and into college. The techniques of tackling and taking on blocks do not change, but the athlete’s time of motion is shorter. Thus increasing the rate of force applied to the skills.

Why the Vertical Jump for the Test?

• Purposeful: The VJ by nature tests an athlete’s ability to generate maximal dynamic force. The change from eccentric to concentric is seamless, which is an essential component of sport.

• Practical: The VJ is an effective tool for a short handed, limited resource coach because it is the closest they can approach absolute, involuntary recruitment of as many muscle fibers in a given task with minimal equipment.

• Prudent: Coach is able to efficiently assess a large number of athletes, all the without having to place a heavy load on the athlete.

Set Up and Execution

1. Measure the athlete’s max reach overhead.
   Have the athlete standing perpendicular to the wall with feet flat on the floor in a tall posture with the arm closest to the wall extended straight overhead. Mark the end point of the fingertips and measure this height from the ground.

2. Counter Jump
   A vertical jump starting from full standing followed by a sudden dip and jump max height.

3. Static Jump
   The vertical jump achieved from a static, knees flexed start at the depth of amortization (dip) phase of jump #1.

Breakdown of Analysis

The explosive strength deficit assessment is performed simply by comparing these two jumps. The difference between the maximal force reached from a stretch shortening start and the maximal force reached from the static, bent knee position start will be evident from the increased resistance and the longer distance traveled from jumps #1 to #2.

Small Deficit
If there is a small difference between your athlete’s two jumps, it is evident that the athlete is proficient in nervous stimulation and may have experience with plyometrics or high intensity, low rep lifting. If this is the case, you have identified that the athlete needs more strength work and hypertrophy must be induced. 5RM-8RM loads and submaximal loading methods common in bodybuilding can be supplemented for this athlete to help increase strength and cross sectional area.

Large Deficit
If there is a large deficit, the athlete may display a history of strength or hypertrophy training with 5RM-8RM loads, but is expressing an inefficient central nervous system and lack of power. If this is the case, an increase in explosive strength may be produced by maximal or near maximal neuromuscular stimulation through plyometrics or olympic weightlifting.

Moderate Deficit
There will be athletes with moderate deficits, and this is the expectation. We strongly support putting them on programs preparing them for the demands in their sport. What you should be looking for in these athletes is an increase in vertical jump height when tested, and use other Power Athlete assessment tools such as the Deadbug to identify other limiting factors to guide program.

Observations
The explosive strength deficit test is also an incredibly useful tool for testing which of your athletes either performed or neglected off-season training regimens. If there is a decrease in overall vertical or a deficit in explosive strength from last test, a coach can determine how to safely and effectively start a de-trained athlete back for pre-season.

In executing and assessing this movement, the focus, like everything with Power Athlete, is on posture and position. Luke did a fantastic breakdown between the Box Jump vs the Vertical Jump. In this write up he brings up the One Joint Rule. One joint means exactly that, no local flexion or extension in the spine. A break in this needs to be the first thing your coach’s eye picks up. An athlete’s ability to maintain posture and position through space is essential for success. This is low hanging fruit for a coach to correct for improving not only the vertical jump, but on the field performance.

Empower your performance

The professional level is looking for developed athletes, and there still seems to be an approach at the developmental levels of “the greater the strength, the better the athlete”. Strong athletes do not necessarily possess a high rate of force development (3), and I’ve witnessed countless examples of the strongest lifters in weight room that are the strongest lifters on the bench come Game Day.

A coach that is able to identify the explosive strength deficit of an athlete through the vertical jump test will be empowered to design the specific type of strength training to accurately address limiting performance factors. Simply picking sets and reps with a given load arbitrarily or forcing reps will not put an athlete in a position to succeed. Gone are the days of applying a one size fits all program to the team and forcing reps that drive no adaptation and risk injury. Effective strength utilization and training means optimally timing the magnitude of force, power and rate of force production throughout any movement (2).

A strength coach must build a program for their team off the demands of their sport and fill in the gaps for each athlete according their limiting factors and specific needs to meet those demands. The explosive strength deficit test, along with many of the other Power Athlete tools, helps identify these needs and direct strength coaches to program effectively for performance where it matters most…On the field!

(1)Hatfield, F.C. (1989). POWER: A Scientific Approach: Advanced Musclebuilding Techniques for Explosive Strength!. Chicago, IL: Contemporary Books, Inc.

(2)Verkhoshansky, Y., & Siff, M. (2009). Supertraing: 6th Edition. Rome: Ultimate Athlete Concepts.

(3)Zatsiorsky, V.M. & Kraemer, W.J. (2006). Science and Practice of Strength Training. Champaign, IL: Human Kinetics.

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