NASM Chapter 11 - Plyometric (Reactive) Training Concepts

Chapter 11 Plyometric Training Concepts:

Know all definitions throughout the chapter
Integrated performance paradigm
The phases of Plyometric Exercise
Figure 11.2 Program design parameters for reactive training
OPT™ Level (adaptation): Stabilization, Strength, or Power (be familiar with all exercises listed, as well as how to regress and progress the exercises listed)
Type of Exercise: Balance
Table 11.1 Plyometric training program design

Also known as jump or reactive training, form of exercise that uses explosive movements such as bounding, hopping, and jumping to develop muscular power.
Plyometric training is type of training where individual reacts to the ground surface in such a way that they develop larger than normal ground forces that can then be used to project body with greater velocity or speed of movement.
Reactive training refers to reaction stimulus clients encounter during plyometric training, which is ground surface in this case, therefore reactive and plyometric are used interchangeably.
Individuals must possess adequate core strength, joint stability, and range of motion and have ability to balance efficiently before performing any plyometric exercises.

What is Plyometric Training?

Enhanced performance during functional activities emphasizes the ability of muscles to exert maximal force output in a minimal amount of time(also known as rate of force production).
Rate of Force Production – Ability of muscles to exert maximal force output in minimal amount of time.
Success in everyday activities and sport depends on speed at which muscular force is generated. Speed of movement is function of training, reactive neuromuscular control is function of learning. Key then is muscular overload and rapid movements during execution of training exercises.
Plyometric (reactive) training – Exercises that generate quick, powerful movements involving an explosive concentric muscle contraction preceded by an eccentric muscle action.
Explosive muscular contractions can be seen in practical instances such as rebounding in basketball.
Integrated Performance Paradigm – Move with efficiency, forces must be dampened(eccentrically), stabilized(isometrically), and then accelerated(concentrically). So muscles must slow down in eccentric phase, pause isometrically, then explosively accelerate in concentric phase.

Three phrases of Plyometric Exercise

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 – Dynamic stabilization and is time between end of eccentric muscle action and initiation of concentric contraction. Prolonged amortization phase results in less than optimal neuromuscular efficiency from a loss of elastic potential energy. Rapid switch from eccentric loading to concentric contraction leads to a more powerful response.
Concentric phase – occurs immediately after amortization phase, involves concentric contraction.

Importance of Plyometric Training

Plyo exercises enhance excitability, sensitivity, and reactivity of neuromuscular system and increase the rate of force production(power), motor unit recruitment, firing frequency(rate coding) and motor unit synchronization.
These exercises can be incorporated once client has achieved an overall strength base, proper core strength, and balance stabilization capabilities.
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. Plyometric training prepares client for functional demands of specific activity.
Plyometric training provides ability to train specific movement patterns in a biomechnically correct manner at more functionally appropriate speed. Ultimate goal of plyometric training is to decrease the reaction time of muscle action spectrum, this is what results in increased speed of movement in the individual.
Speed of muscular exertion is limited by neuromuscular coordination. Means that the body will only move within a range of speed that the nervous system has been programmed to allow. Plyo training improves neuromuscular efficiency and improves range of speed set by CNS.
Often overlooked in traditional training programs.

Stabilization Exercises

Involve little joint motion. Designed to establish optimal landing mechanics, postural alignment, and reactive neuromuscular efficiency(coordination during dynamic movement). When individual lands they should hold the landing position for 3 to 5 seconds.
Exercises: Squat jump with stabilization, box jump-up with stabilization, box jump-down with stabilization, multiplanar jump with stabilization

Plyometric Strength Exercises

Exercises involve more dynamic eccentric and concentric movement through a full range of motion. 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. 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. Designed to further improve the rate of force production, eccentric strength, reactive strength, reactive joint stabilization, dynamic neuromuscular efficiency, and optimal force production. Performed as fast and explosively as possible.
Exercises: Ice-skaters, single-leg power step-up, proprioceptive plyometrics.