# Why All Athletes Need Plyometrics

Studies have shown that plyometric training improves speed, strength, power and jumping ability, all of which are crucial for sports.

You have probably heard of plyometrics if you play any sport that involves jumping. Do you know why plyometric training is so important?

Plyometrics occur in any sport that involves cutting, change of direction, sprinting and jumping. The most common sports we see utilize plyometric training are basketball, volleyball, soccer and football. Studies have shown that plyometric training improves your speed, strength, power and jumping ability, all of which are crucial for sports.

In short plyometrics is the action of jumping, bounding, hopping or skipping. However, this action must have a rapid reactive component to it. Skipping is a perfect example of plyometrics because as the foot lands it is preparing to skip right back up, leading to that rapid reactive component that we mentioned.

You have probably heard of plyometrics if you play any sport that involves jumping. Do you know why plyometric training is so important?

Plyometrics occur in any sport that involves cutting, change of direction, sprinting and jumping. The most common sports we see utilize plyometric training are basketball, volleyball, soccer and football. Studies have shown that plyometric training improves your speed, strength, power and jumping ability, all of which are crucial for sports.

## What Exactly Is Plyometrics?

In short plyometrics is the action of jumping, bounding, hopping or skipping. However, this action must have a rapid reactive component to it. Skipping is a perfect example of plyometrics because as the foot lands it is preparing to skip right back up, leading to that rapid reactive component that we mentioned.

The rapid reactive component is the stretch-shortening cycle, which is an active eccentric stretch followed by an immediate concentric contraction. In other words it is like a spring in which you first stretch the spring to create potential energy then it is released into active energy. Now that we know what plyometrics are and what formulates it, we are going to go over a 4-step progression in developing this stretch-shortening cycle needed for plyometric training.

## Step 1: Eccentric Jumping

In this phase we must teach the athlete the correct landing mechanics and how to stick the landing. We often preach to an athlete that you must have good brakes in a fast car or else it is a recipe for disaster. Furthermore the majority of non-contact injuries occur during the deceleration phase of activities, such as landing and cutting.

The ultimate goal of these exercises is to improve the athlete's ability to withstand the downward velocity and eccentric load of plyometric activities, which is crucial in developing the stretch-shortening cycle. The biggest cue that we give our athletes is to "land softly," which will allow them to actively absorb the shock. Also, we have the athlete "freeze" to observe if there are any faults with their landing mechanics, such as dynamic knee valgus (femoral adduction/internal rotation) or lack of knee/hip/trunk flexion.

In the video below we show variations of eccentric jumping. Prior to having the athlete land from a box, we teach them how to perform snap downs with a medicine ball to simulate landing from a box to teach proper landing mechanics. Once they demonstrate proper technique with the snap down, they should be progressed to landing from a box.

Coaching Cues:

• Land as softly as you can
• Freeze at the bottom/Stick the landing
• Bend at the hips, knees, and trunk
• Don't let your knee cave in

## Step 2: Low Intensity Fast Plyometric Jumps

In this phase the main goal is to introduce the spring and release concept of the stretch shortening cycle.

The goal of this fast plyometric exercise is to reduce ground contact time. In other words the leg should act like a spring and rebound with minimum delay off the ground.

A coaching cue we like to use is to tell the athlete to imagine that the ground is a hot surface and the goal is to get off the floor as quickly as possible. The athlete should aim to stay on the balls of their feet; this will allow the athlete to pre-activate the lower leg muscles before landing, allowing them to enable the "stiff-spring" response.

In the video below we demonstrate three exercises: Double-Leg Ankle Hops, Single-Leg Ankle Hops and skipping to use as low intensity, fast plyometric exercises.

Coaching Cues:

• Imagine that the ground is a hot surface
• Get off the floor as quick as possible
• Stay on the balls of your feet
• Minimize knee bending

## Step 3: Hurdle Jumping

Once the athlete understands the concept of the fast plyometric jump, they are progressed to hurdle jumping, a continuation from the prior phase. The goal is the same—to minimizing ground contact time—however we are introducing height as a parameter in this phase.

Once the athlete is able to clear at least four hurdles with minimal ground contact time, the height of the hurdle may be increased to produce an overload effect. In the video below we show hurdle jumping with both single-leg and double-leg jumping.

Coaching Cues

• Imagine the ground is a hot surface
• Stay on the balls of your feet
• Fixed jump height across all hurdles

## Step 4: Depth Jumping

The main goal of this phase is minimizing ground contact time and maximizing jump height.

The Depth Jump is a great exercise that will help develop that, but too often athletes are performing this exercise without going through the necessary progressions to get to this.

In the Depth Jump we can measure the Reactive Strength Index, or RSI, which measures the athlete's ability to change quickly from an eccentric (load acceptance) to concentric contraction (convert passive to active energy; loaded spring analogy). This can be seen as the athlete's "explosiveness."

Explosiveness has been used to describe an athlete's ability to develop maximal force in minimal time. In the NBA, people often comment that Zion Williamson is so explosive—it is because of his ability to jump high at a fast rate. The goal for every athlete is to have a ground contact time around .25 seconds, which research has shown to be the gold standard of a fast short stretch cycle. That time is the measurement between your feet touching and leaving the ground.

In the video below we show variations of both a single-leg and two-leg Depth Jump. The box should be between 8-16 inches tall. The progression of this exercises is to increase the box height if the athlete is able to achieve .25 seconds of ground contact time.

Coaching Cues:

• Jump fast, Jump high
• Imagine the ground is a hot surface
• Try this 4-step progression for your athletes when you are introducing them to plyometrics.

Sources:

Brazier J, et al. "Lower extremity stiffness: Considerations for testing, performance enhancement, and injury risk." Journal of Strength and Conditioning Research, 2019

Flanagan, E and Comyns T. "The use of contact time and the reactive strength index to optimize fast stretch shortening cycle training". 2019

Photo Credit: BartekSzewczyk/iStock