NASM Chapter 11 Plyometric (Reactive) Training Concepts

Principles of Plyometric Training

  • Plyometric training is also known as jump or reactive training, it is a form of exercise that uses explosive movements such as bounding, hopping, and jumping to develop muscular power.
  • Plyometric (Reactive) Training
    Exercises that generate quick, powerful movements involving an explosive concentric muscle contraction preceded by an eccentric muscle action.
  • Clients need to pass the core and balance portions of training before even considering this phase
  • Rate of Force Production
    Ability of muscles to exert maximal force output in a minimal amount of time. (This is one of the major benefits of Plyometric training)
  • Plyometric training uses a characteristic of muscle known as the stretch-shortening cycle  of the Integrated Performance Paradigm – essent1
  • Integrated Performance Paradigm
    To move with efficiency, forces must be dampened (eccentrically),stabilized (isometrically), and then accelerated (concentrically).


3 Phases of Plyometric Exercise

  • The 3 phases include– Eccentric (Loading phase). Amortization (Transition Phase) and the Concentric (Unloading phase)
  • Eccentric Muscle Action
    An eccentric muscle action occurs when a muscle develops tension while lengthening.
  • Eccentric Phase
    First stage of plyometric movement, classified as eccentric phase, but also called deceleration, loading, yielding, counter movement, or cocking phase. Phase increases muscle spindle activity by prestretching the muscle before activation. Potential energy stored in the elastic components of the muscle during this loading phase much like stretching a rubber band.
  • Amortization Phase
    1. This phase involves Dynamic stabilization and is time between end of eccentric muscle action (loading) and initiation of concentric contraction (unloading).
    2. Prolonged amortization phase results in less than optimal neuromuscular efficiency from a loss of elastic potential energy. (Think of preparing to jump- holding the bending of the knees prior to jumping is the amortization phase)
    3. A Rapid switch from eccentric loading to concentric contraction leads to a more powerful response.
  • Concentric phase
    1.This is the last phase of the paradigm before another starts- the concentric phase occurs immediately after amortization phase and involves a concentric contraction.
    2. This is synonymous with releasing a rubber band after it was stretched

Importance of Plyometric Training

  • Plyometric exercises enhance excitability, sensitivity, and re-activity of neuromuscular system and increase the rate of force production(power), motor unit recruitment, firing frequency(rate coding) and motor unit synchronization.
  • All movement patterns that occur during functional activities involve a series of repetitive stretch-shortening cycles(eccentric and concentric contractions).
  • Stretch-shortening cycles require neuromuscular system to react quickly and efficiently after an eccentric muscle action to produce a concentric contraction and impart necessary force(or acceleration) in the appropriate direction.
  • By training the client with functional movements such as “Cutting or Change-of-direction)- Plyometric training prepares client for functional demands of specific activity.
  • The Speed of muscular exertion is limited by neuromuscular coordination- This means that the body will only move within a range of speed that the nervous system has been programmed to allow.
  • Optimal reactive performance of any activity depends on the speed at which muscular forces can be generated – Plyometric training assists with increasing these speeds


  • The Nervous system recruits muscles only at speeds at which it has been trained to do so. If it is not trained to recruit muscles quickly, when met with a demand for fast reaction, the nervous system will not be able to respond properly.
  • This reiterates the importance of using a progressive systematic approach when designing the plyometric component of your client’s training regimen.

Designing a Plyometric Training Program

  • A plyometric program is a vital component of any integrated training program.
  • This program must be systematic and progressive.
  • Plyometric training should only be performed by individuals wearing supportive shoes, and on a proper training surface such as a grass field, basketball court, or tartan track



Levels of Plyometric Training

  • There are 3 levels of training within the NASM’s OPT model-
    1. Stabilization
    2. Strength
    3. Power

Plyometric Stabilization Exercises

  • In plyometric-stabilization training, exercises involve little joint motion. They are designed to establish optimal landing mechanics, postural alignment, and reactive neuromuscular efficiency (Coordination during dynamic movement).
  • When an individual lands during these exercises, he or she should hold the landing position (Or stabilize) for 3-5 seconds.
  • During this time individuals should make any adjustments necessary to correct faulty postures before repeating the exercise
  • Exercises- Squat jump with stabilization, box jump-up with stabilization, box jump-down with stabilization, multiplanar jump with stabilization

Example Plyometric Exercises




Plyometric Strength Exercises

  • Exercises involve more dynamic eccentric and concentric movement through a full range of motion.
  • The Specificity, Speed, and Neural demand may also be progressed at this level.
  • Exercises are intended to improve dynamic joint stabilization, eccentric strength, rate of force production, and neuromuscular efficiency of the entire human movement system.
  • Training is performed in repetitive fashion(spending relatively short time on the ground before repeating the drill).
  • Exercises: Squat jump, tuck jump, butt kick, power step-up

Plyometric Power Exercises

  • Exercises involve entire muscle action spectrum and contraction-velocity spectrum used during integrated, functional movements.
  • This approach to training is designed to further improve the rate of force production, eccentric strength, reactive strength, reactive joint stabilization, dynamic neuromuscular efficiency, and optimal force production.
  • Exercises are performed as fast and explosively as possible.
  • Exercises: Ice-skaters, single-leg power step-up, proprioceptive plyometrics.

NASM-Table-11.1 (1)




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