Lecture 13 Flashcards
Terminology associated with the sacromere:
- myosin filament
- actin filament
- cross-bridge
- power stroke
Rate of ATP hydrolysis depends on ….
myosin heavy chain (MHC) type
Type I MHC:
slow hydrolysis rate
Type IIa MHC:
fast hydrolysis rate
Type IIb MHC:
very fast hydrolysis rate
Cross-bridge cycling 4 steps:
- myosin heads split ATP and become reoriented and energized
- myosin heads bind to actin forming crossbridges
- myosin heads rotate toward centre of the sacromere (power stroke)
- as myosin heads bind ATP, the crossbridges detach from actin
MHC I –>
Type I
MHC IIa –>
Type IIA
MHC IIb –>
Type IIB
Biceps brachii is ___% Type I and ____% Type II.
- 50%
- 50%
Deltoid is ___% Type I and ____% Type II.
- 60%
- 40%
Gluteus maximus is ___% Type I and ____% Type II.
- 50%
- 50%
Vastus Lateralis is ___% Type I and ____% Type II.
- 50%
- 50%
Biceps femoris is ___% Type I and ____% Type II.
- 60%
- 30%
Gastrocnemius is ___% Type I and ____% Type II.
- 50%
- 50%
Soleus is ___% Type I and ____% Type II.
- 90%
- 10%
Tibialis anterior is ___% Type I and ____% Type II.
- 70%
- 30%
Erector spinae is ___% Type I and ____% Type II.
- 50%
- 50%
Type I muscle fibre: neural, metabolic, other name.
- slow twitch
- oxidative
- slow oxidative
Type IIa muscle fibre: neural, metabolic, other name.
- fast twitch
- oxidative/glycolytic
- fast oxidative glycolytic
Type IIb muscle fibe: neural, metabolic, other name.
- fast twitch
- glycolytic
- fast glycolytic
Muscle fibre is made up of ______ in ____ and in ____.
- sacromeres
- series
- parallel
Length of muscle =
number of sacromeres in series
Force generated by muscle =
number of sacromeres in parallel
Time to contract =
MHC type
Sacromere:
space between 2 Z discs
Effects of flexibility training on performance: increased:
- sit and reach
- standing long jump distance
- vertical jump height
- knee flexion strength
- knee extension strength
Effects of flexibility training on performance: decreased:
20 m sprint time
Type I adaptations to resistance exercise:
- no effect on MHC
- minimal or small increase in sacromeres in parallel
- increased oxidative capacity (metabolic)
- less fatiguable
Type IIA adaptations to resistance exercise:
- no effect on MHC
- large increase in sacromeres in parallel
- increase oxidative and glycolytic capacity (metabolic)
- less fatiguable
Type IIB adaptations to resistance exercise:
- MHC: convert to IIA with training
- type IIA fibres convert to type IIB with disuse
Maximum flexibility depends on…
number of sacromeres in series
Maximum strength depends on…
number of sacromeres in parallel
Maximum power depends on…
- number of sacromeres in series
- number of sacromeres in parallel
- % MHC IIa
Caveat:
ignores neural activation of muscle
MU =
motor unit
Terminology associated with the motor neuron:
- neuron body
- axon
- dendrite
- meylin sheath
- neuromuscular junction
Individuals may not maximally ______ muscle via _____ ____.
- activate
- voluntary effort
Estimated voluntary muscle activation: ____%. Why?
- 75% (range 60-100%)
- neural inhibition (eg. Golgi tendon organ)
Why neural inhibition?
prevent injury (muscle-tendon tear, avulsion fracture)
Size principle: Type I (SO) motor unit:
- slow twitch
- small # muscle fibres
- low recruitment threshold
- lower force
Size principle: Type II (FOG) motor unit:
- fast twitch
- large # muscle fibres
- high recruitment threshold
- higher force/time
Size principle: Type II (FG) motor unit:
- fast twitch
- very large # muscle fibres
- very high recruitment threshold
- highest force/time
Adductor pollicis is ___% Type I and ____% Type II.
- 80%
- 20%
Type I (SO) motor unit effect of hypertrophy:
- small increase size of muscle fibres
- small increase recruitment threshold
Type II (FOG) motor unit effect of hypertrophy:
- increase size of muscle fibres
- increased recruitment threshold
Type II (FG) motor unit effect of hypertrophy:
- increase size of muscle fibres
- increased recruitment threshold
Muscle hypertrophy:
- increased muscle fibre and motor unit size
- greater resistance force is required to recruit motor units
With muscle hypertrophy, for the same absolute resistance force…
- fewer motor units are used
- lower ATP cost
- increased force steadiness
Twitch:
motor unit activated once
Summation of twitches:
motor unit activated again before relaxation
Unfused tetanus:
motor unit activated repetitively at low frequency
Fused tetanus:
motor unit activated repetitively at high frequency
MU activation: non ballistic (slow and steady) step 1:
- 0-40% 1RM
- incremental recruitment of type I motor units @ low firing frequency
MU activation: non ballistic (slow and steady) step 2:
- 40-90% 1RM
- incremental recruitment of type II motor units @ low firing frequency
MU activation: non ballistic (slow and steady) step 3:
- 90-100% 1RM
- increase in firing frequency of type I and type II motor units
MVC =
maximal voluntary contraction
In MU activation - ballistic, motor units are recruited according to ____ _____.
size principle
In MU activation - ballistic, firing frequency of motor units is higher at the time of _____.
recruitment
MU activation - ballistic means:
compromise max force (80-90% MVC)
Rest in sarcolemma:
Na, K ATPase pump maintains ion balance across sarcolemma
Muscle twitch in sarcolemma:
- sodium enters cell
- potassium exists cell
High frequency activation in sarcolemma:
Na, K ATPase pump restores ion balance to allow repeated activation of muscle
Na, K ATPase has _____ transport of…
- active
- Na out of muscle fibre
- K into muscle fibre
Na, K ATPase requires ____.
ATP
1 ATP =
3 Na & 2 K
What increases # of Na K ATPase pumps?
- high intensity training
- resistance exercise
- sprint interval training
Non-ballistic has ____ muscle activation while ballistic has _____ muscle activation.
- slow
- fast
Non-ballistic has ____ rate of force development (RFD), while ballistic has _____ RFD.
- low
- high
Non-ballistic has _____ energy expenditure while ballistic has ____ EE.
- lower
- higher
Non-ballistic has _____ force steadiness while ballistic has ____ force steadiness.
- greater
- lower
Non-ballistic neuromuscular training:
- muscular endurance
- hypertrophy
- neurologic strength
Non-ballistic neuromuscular training: 0-40% MVC:
- MU activation: recruit type I (SO) MU
- training results: type I (SO) & II (FOG) MU: inc. hypertrophy and endurance
Non-ballistic neuromuscular training: 40-70% MVC:
- MU activation: recruit type II (FOG) MU
- training results: type I (SO) & II (FOG) MU: inc. hypertrophy and endurance
Non-ballistic neuromuscular training: 70-90% MVC:
- MU activation: recruit type II (FG) MU
- training results: Type II (FOG & FG) MU: inc. hypertrophy and endurance
Non-ballistic neuromuscular training: 90-100% MVC:
- MU activation: increase firing frequency of all MU
- training results: inc. neurologic strength; minimal hypertrophy
Ballistic neuromuscular training: 0-40% MVC:
- MU activation: recruit type I (SO) MU @ max firing frequency
- Training results: increase speed @ low resistance
Ballistic neuromuscular training: 40-70% MVC:
- MU activation: recruit type I (SO) & Type II (FOG) MU @ maximum firing frequency
- training results: increase speed @ low-moderate resistance
Ballistic neuromuscular training: 70-90% MVC:
- MU activation: recruit type I (SO) & type II (FOG & FG) MU @ maximum firing frequency
- training results: increase speed @ low-moderate-high resistance
Ballistic neuromuscular training:
- low load explosive training
- moderate load explosive training
- high load explosive training
General resistance exercise parameters for training to improve strength: beginners:
- intensity: 60-80% 1RM
- sets: 2-4
- training frequency: 3 days/week
General resistance exercise parameters for training to improve strength: moderately trained:
- intensity: 80% 1RM
- sets: 4-5
- training frequency: 2 days/week
General resistance exercise parameters for training to improve strength: advanced:
- intensity: > 85% 1RM
- sets: 4-8
- training frequency: 2-3 days/week
Muscular endurance exercise parameters:
- intensity: 70-80% 1RM
- reps: 8-12
- speed: slow
Hypertrophy exercise parameters:
- intensity: 80-90% 1RM
- reps: 5-8
- speed: slow
max/neurologic strength exercise parameters:
- intensity: > 90% 1RM
- reps: 1-3
- speed: slow
Ballistic exercise parameters:
- intensity: 30-80% 1RM (depends on type of exercise)
- reps: 1-3
- speed: fast
Intensity aka
recruitment threshold
Reps/sets aka
motor unit fatigue
Speed aka
firing frequency @ recruitment
2 methods for intensity:
- % 1RM (repetition maximum)
- repetition maximum method
% 1RM (repetition maximum):
intensity assigned as percentage of max. resistance lifted for one repetition
Repetition maximum method:
intensity assigned as maximum resistance lifted for a number of repetitions
Ballistic training types:
- sprinting
- implement & jump
- weightlifting
Method for sprinting intensity:
% of best sprint time
Range for sprinting intensity:
70-100% best sprint time
Method for implement & jump intensity:
% 1RM of similar non-ballistic exercise
Range for implement & jump intensity:
30-80% 1 RM of non-ballistic exercise
Method for weightlifting intensity:
% 1 RM
Range for weightlifting intensity:
70-100% 1RM
Intermuscular coordination:
- coordination between muscles/muscle groups
- improved activation of syngergists
- decreased co-contraction of antagonists
Intermuscular coordination is associated with _____ fitness.
- neuromotor
- skill, technique
Flexibility training protocol:
- optimal protocol not identified
- 15s = 45s = 120s
- passive = active