Lecture 22 : Plyometrics Flashcards
(70 cards)
plyometric exercise refers to
dynamic activities that enable a muscle to reach maximal force in a very short time
plyometric training is considered a technique in what training
power / speed strength training
plyometric exercise is a quick powerful movement using a …
pre stretch or countermovement that utilises the stretch shortening cycle and myostatic reflexes
what is the goal of plyometric exercise
reduce the amortisation period or the coupling time between eccentric and concentric phases of the stretch shortening cycle
what are the phases to the stretch shortening cycle and what happens
eccentric : stretch of agonist
amortization : pause between phases 1 and 3
concentric : shortening of agonist fibres
what is hysteresis in terms of the force and length graph of a movement (SSC)
the area inside the loop on the graph
this is the energy that is lost during the stretch cycle
what is the area under the curve in terms of the force and length grace of a movement (SSC)
underneath the curve is the energy that is returned to the system
this is what we want to optimise
goal of plyometric training in terms of force length graph
want to narrow the loop and increase the area under the curve
trying to reduce the amorization time and speed up the contraction
why is hysteresis good
good for protection
longer for the muscle to return, taking more time to unload
plyometrics dont convert slow twitch to fast twitch, but they
improve functional characteristics of fast fibres
induce neural adaptations that increase type II fibre activation and coordination
some studies suggest that high intensity explosive training can cause increased expression of … (fibre type)
type IIa myosin heavy chain proteins
how can plyometrics possibly reverse some of our power adaptations
might actually convert some IIx to IIa so could possibly reverse some of our power adaptations
why do you need a good foundation of power before training plyometrics
want a good foundation in power as you may lose some of the IIx fibres so you aren’t left less powerful
plyometric training is effective in increasing …… and …… (this is important for speed)
effective in increasing fascicle length of the vastus lateralis and rectus femoris muscles and the pennation angle of the rectus femoris muscle
in trained individuals plyometrics can improve …. with only ….
improve explosive force with only minimal increase in muscle girth
how is explosive force increased through plyometrics
tuning the excitability of corticospinal tract for type II motor units
increases recruitment and activation for type II motor units
increased activation of fast twitch motor units and higher rate of firing
how does fibre profile shift in plyometric training
type IIx > type IIa
three broad neural adaptations of plyometrics
wire together fire together
golgi tendon organ becomes desensitised
greater synergist coordination, co activation of muscles needed to stabilise the limb
why is wire together fire together important in plyometric training
want to choose exercises that are similar as possible to the athletes needs
explain how the golgi tendon organ becomes desensitised with plyometric training and what this means
golgi tendon inhibition : higher threshold for muscle tension and activation, thus increasing power of muscle contraction
so we can allow for more powerful force of contraction without inhibition of the muscle
what is valgus collapse
knee collapses in and rotates
what sports should do plyometrics
that involve jumping, sprinting, change of direction or agility
plyometrics are highly coordinated and skilful movements how is this important for who should do plyometrics (5)
age and physical development of the athlete
skills and techniques involved in plyometric exercise
principle performance factors of the sport
energy requirements of the sport
training phase of the annual plan
what is the pre training criteria for plyometrics (baseline strength)
squat 1.5 x body weight
bench press at least 1 x body weight for large athletes or 1.5 x for smaller athletes
