KNES 360: Ch 18 Plyometrics

~maximal jumps
~no breaks

two important components of plyometrics

~vertical
~lateral
~horizontal (forward/back)
~diagonal

directional components of plyometrics

~eccentric load is heavier
~trigger greater stretch response
~trigger greater concentric response

why is it important that plyos have no breaks between jumps?

approximately 100

typical plyo workout has how many contacts

no

do athletes produce max force development during sport?

athlete who is plyo trained

if you have two linebackers but one of them is plyo trained, who can produce more force?

plyos allow for strength training to be applied on the field

how do plyos affect athletes

a rapid stretch

what increases the elastic energy in musculotendinous components

energy is stored

what happens to the elastic energy in musculoskeletal components after the rapid stretch

the stored energy is released contributing to the total force production

if a concentric muscle action follows immediately

rapid stretch into a rapid contraction

foundation of all plyos

SEC series elastic component

when stretched (eccentric) this stores elastic energy that increases the force produced; workhouse; primarily the tendon

CC contractile component

the primary source of muscle force during concentric muscle action (actin, myosin, crossbridges)

PEC parallel elastic component

structure that exerts a passive force with unstimulated muscle stretch (epimysium, perimysium, endomysium, and sarcolemma)

mechanical and neurophysiological

2 mechanical models of plyometrics

neurophysiological model of plyometrics

model that involves potentiation of the concentric muscle action by use of the stretch reflex

potentiation

change in the force-velocity characteristics of the muscle's contractile components caused by stretch

stretch reflex

the body's involuntary response to an external stimulus that stretches the muscles

extrafusal muscle fibers

contracting fibers in the muscle

intrafusal muscle fiber (muscle spindle)

deeply embedded fibers that sense stretch but also contracts

stretch-shortening cycle

involves both models of plyos; employs both energy storage of SEC and stimulation of stretch reflex to facilitate maximal increase in muscle recruitment over a minimal amount of time

muscle recruitment and activity resulting from the SSC

a fast rate of musculotendinous stretch is vital to

eccentric, amortization, concentric

3 parts of the stretch shortening cycle

eccentric

stretch of agonist muscle

amortization

pause between eccentric and concentric phases

concentric

shortening of agonist muscle fibers

SSC; rapid eccentric muscle action stimulates the stretch reflex and storage of elastic energy, which increases the force produced during subsequent concentric action

basis of all plyometric exercises

~sport
~sport position
~training status

athletes must be evaluated for

~lower body
~upper body
~trunk

types of plyos

exercise movements must be shorter and quicker to allow stimulation and use of stretch reflex

what is an important consideration when doing trunk plyos

plyometric intensity

the amount of stress placed on muscles, connective tissue, and joints

the type of drill

what is plyometric intensity controlled by

volume should decrease

as plyo intensity increases

single leg lower body plyos place more stress on muscles, connective tissues, and joints than double leg plyos

How do points of contact affect plyometric intensity?

greater speed increases the intensity

how does speed affect plyometric intensity

the higher the body's center of gravity, the greater the force on landing

how does height of the drill affect plyometric intensity

greater body weight the more stress on muscles, connective tissue, and joints. external weight can be added to increase a drill's intensity

how does body weight affect plyometric intensity

48-72 hrs between plyo sessions; 2-3 sessions per week

typical recovery time guideline for plyos

1:5 to 1:10

work to rest ratio

longer rests between sets; promote recovery so the next set can still utilize maximal power; prevent fatigue

describe the length of rest you want for plyo exercise

volume

foot contacts per workout (or in distance for bounding drills)

number of throws or catches per workout

how is volume counted for upper body drills

80-100

volume for a beginner

100-120

volume for an intermediate

120-140

volume for advanced

increasing the intensity (resistance), frequency, or duration of the training above the levels normally expected

overload principle

6-10 weeks

how long is a typical plyo program

4 weeks

vertical jump may improve after how many weeks of plyo training

prepubescent and adolescent children

depth jumps and high-intensity lower body plyometrics are contraindicated for which population

yes under proper supervision and with an appropriate program

can prepubescent and adolescent children do plyometrics

no more than 5: avoid high intensity

plyo program for master should include no more than _ low to moderate intensity exercises

lower; include fewer total foot contacts than standard plyo training program

volume for the masters

3-4 days

recovery time for masters

lower body resistance + upper body plyos
upper body resistance +lower body plyos

how would you combine plyos and resistance training

no; but some advanced athletes may benefit from it

should you combine heavy resistance training and plyos on the same day

aerobic exercise may have a negative effect on power production

why would you do plyos before aerobic endurance training

~proper footwear
~proper landing technique (injury prevention & increase performance )

when doing a pretraining evaluation of the athlete, what are you looking for technique wise

bench body weight and squat 1.5x bodyweight

before you can do plyos, how much should you be able to bench and squat

standing - double and single leg
quarter squat - double and single leg
half squat - double and single leg

3 balance tests done to clear an athlete for plyos

30 sec each

how long are the balance tests held for

balance on one leg for 30 sec without falling

an athlete just starting plyometrics should be able to

hold a single leg half squat for 30 sec without falling

an athlete beginning an advanced plyo program should be able to

its harder to decelerate and then jump again ***its hard but technically still possible

why should athletes who weigh > 220 pounds not perform depth jumps from heights > 18 inches

surface must have adequate shock absorbing properties to prevent injuries

what kind of landing surface do you need for plyometrics