power training 1 Flashcards
athletic performance is donimated by a combination of what abilities
biomotor
what are the 3 factors with in biomotor abilities
strength and force
speed
endurance
what is the definition of strengh
maximam force developed by the contracting muscle
ability of a muscle to produce stress or force
what is the definition of power
the rate of muscular force production over the range of motion in a specific time period
for neural control when muscle force is greater when
a) more motor units are involved in a contraction
b) the motor units are greater in size
c) the rate of firing is faster
strength and power when looking at muscle cross sectional area
the force a muscle can exert is related to its cross-sectional area rather than to its volume
strength and power when looking at arrangement of muscle fibres
variation exists in the arrangement and alignment of sarcomeres in relation to the long axis of the muscle
what is a dynamic contraction
produced movement of a skeletal body part such as an upper or lower limb or the trunk
what are the two types of dynmic contractions
concentric and eccentric
what is static contraction
muscle activation without observable change in muscle fibre length
what type of contraction is the static
isometric
what happens at a resting length for the muscle length
1) actin and myosin filament lie next to each other
2) maximal number of potential cross-bridges sites available
3) muscle can generate the greatest force
what happens when stretched for the muscle length
1) a smaler proportion of the actin and myosin filaments lie mext to each other
2) fewer potential cross-bridge sites available
3) muscles cannot generate as much force
what happens when contracted for the muscle length
1) the actin filaments overlap
2) the number of cross-bridge sites is reduced
3) decreased force generation capability
the length-tension (force) curve what is it
optimal length at which muscle fibres generates their maximal force
total amount of force developed depends on the total number of myosin crossbridges interacting with active sites on the actin
what is the difference between the less the optimal and more length less force curve
less - less crossbridge interaction
optimal - max crossbridge interaction, max force
more length - less crossbridge interaction = less force
the power output equasion
power output= force X velocity
what is dynamic strength
the ability of muscle to exert force at a specific velocity
what are the 4 main requirements for number of athlete of athletic skills in power
1) maximal force that develops
2) how fat force can be developed
3) activation of ssc
4) neural co-ordination of movement
anaerobic training can be what ttype of training
weight training plyometric drills speed training agility training interval training
what adaptations occur after restistance training
increase in muscular strenght/endurance aerobic stays the same increase in rate of force production increase in vertical jump increase in anaerobic power increase in sprint speed
what are acute responses to exercise
acute hypertrophy
what are chronic adaptations to exercise
repeated stress
over compensation
chronic muscle hypertrophy
what are the 6 factors that influence muscle mass
- genetics
- physical activity
- nutritional status
- endocrine infulences
- enviromental factors
- nervous system activation
what are the neural adaptations to exercise
central adaptations
motor units
neuromuscular junction and reflex potentiation
anaerobic training and electromyography studies
what are the central adaptations to the neural adaptations
motor cortex activity increases when the level of force developed increases and when new exercises or movements are being learned
where does neural changes for anaerobic training occur
along the descending corticospinal
where may the motor nurons intervate between
100
what is the size principle
the recruitment and derecruitment of motor units is governed by the size principle
what is selective recruitment
selective recruitment allows inhibition of lower threshold motor units to activate higher threshold units
what are 3 possible changes with trining concerning neuromuscular junction (nmj)
1) increased area of nmj
2) more dispersed, irregularly shaped synapses and a greated total length of nerve terminal branching
3) increased end plate perimeter and area as well as great dispersion of acetylcholine receptors within the end plate
what are the neuromuscular reflex potentiation adaptations
anaerobic training may enhanced the reflex responce, thereby enhancing the magnitude and rate of force development
what are 4 muscular adaptation
- muscular growth
- fiber size changes
- fibre types transitions
- structural and architectural change
muscular growth is refered to as
muscle hypertrophy
what is hyperplasia
is an increase in the number of muscle fibres via longitudinal fibre splitting
hypertrophy involves what
actin and myosin
the myofilamients are added to
the external layers of the myofibril resulting in an increase in its diameter
resistance training results in increases wht fibre types
types one and type 2
what fibre type is greater in size
type 2
muscle growth uses the protein balance shift what is it
mainly enhances protein synthesis
however some decreases in protein degradation increased number nuclei to manage new protein
insulin like growth factors (IGF-I) skeletal muscle over load or eccentric muscle mean what?
local production
includes mecano-growth factor MGF
within hours of resistance training session: increases MGF
MGF activates satellite cells by
either proliferate and becomes new nuclei
or becomes myoblasts, fuse with existing protien filiments to form new contractile protein
what is te fibre type transition
IIx –> IIax –> IIa –> IIac –> IIc then IIc
what does resistance training increase wen looking at structural and architecturl changes
myofibrillar volume cytoplasmic density sarcoplasmic reticulum t-tuble density sodium-pottassium atpase activity
what can be other muscular adaptations
reduce mitochondrial density
decrease capillary density
increase buffering capacity
changes in muscle substrate content
