Skeletal Muscle Plasticity Flashcards
6 factors that improve muscle mass and strength
1) genetics
2) nervous system activation
3) physical activity
4) nutritional activity
5) endocrine influences
6) environmental factors
You can switch from one fiber type to another. T/F
False
You can increase the proportion of the fiber types. T/F
True
Myofilament packing
Increase # in the myofilament and increases the # of cross-bridges that may be formed for the same PCSA
Type 2 myofilament are usually bigger. T/F
True
PCSA calculation involves
Perpendicular to AOR of muscle
Muscle mass
Fiber length
Muscle fiber and force production
May lose force at angle but can pack more force overall
If you’re increasing size of muscles through hypertrophy, it’s also increasing contractile proteins. T/F
True
Mitochondria will increase w/ hypertrophy. T/F
False!
Mitochondria will increase with endurance training. T/F
True
Will there still be mitochondria adaptation with endurance training and RT?
Yes
What is the largest factor the determine’s one’s predominant muscle fiber distribution?
Genetics
PRT may results in fiber type transformation from Type 2B to 2A. T/F
True
Endurance training alters fiber type transition. T/F
False! No type 1 to 2 vice versa…
Being immobilized can shift from Type 2A to 2B. T/F
True
Around how weeks do neural and hypertrophy crosses over?
4-6 weeks
Significant hypertrophy is seen after how many weeks?
6 weeks
New stimulus to muscle can altar neural adaptations. T/F
True
5 neural changes that improve strength!
1) increase number of motor units recruited
2) increase the firing rate (frequency) of the MU
3) increase MU synchronicity (coordinating the firing)
4) increase activation of synergistic muscles
5) increase inhibition of antagonist muscles
3 hypertrophic factors
1) hypertrophy
2) crease proportion area of type 2/ type 1 fibers
3) increase myofilament packing
How much muscle mass increase compared to resting cals lost a day?
1 kg = 25 kcal/day
Higher HR = Higher calories burned T/F
True
EPOC
Oxygen consumption goes during exercise and in recovery from exhaustive exercise
High interval training
How many calories do you expend for every liter of O2 consumed?
5
We can’t get ATP in fast enough to use O2. T/F?
True
The more well-trained you are the less lactate you build up and better clearance, less EPOC effect. T/F
True
Muscle fiber types can’t be changed b/c
The innervation cannot be changed!! Nerves can be transposed. Unless surgery.
M.fibers of type 1 have lower frequency so if it electrically gets stim with high frequency it can get change to type 2.
True
RT in older adults will have 5-10% increase in strength after 4 weeks. T/F
True
Training fast or slow velocity results in a different ability to generate force. T/F
True
Training at fast velocities results in improvements only at high velocities. T/F
True
Baseball players
Training at slow velocities improves across all speeds. T/F
True
Most people
NM inhibition may be derive from (3)
1) unpleasant past experience
2) overly protective home environment
3) free of injury
Are there neural adaptations in endurance trianing?
Yes, small amount
As you train a contracted muscle will have less EMG activity during rest and increase during contraction. T/F
True
Are there more EMG in eccentric or concentric?
Concentric
25% less in Eccentric, less neural innervation to hand the same load
If EMG is higher and force production is higher
Neural adaptation taken place
EMG same, force gets up
Due to hypertrophy!
Can you use EMG to measure neural (strength changes) and hypertrophic factors?
Yes!!!
