Skeletal Muscle Plasticity

Question 1

6 factors that improve muscle mass and strength

Answer 1

1) genetics
2) nervous system activation
3) physical activity
4) nutritional activity
5) endocrine influences
6) environmental factors

Question 2

You can switch from one fiber type to another. T/F

Answer 2

False

Question 3

You can increase the proportion of the fiber types. T/F

Answer 3

True

Question 4

Myofilament packing

Answer 4

Increase # in the myofilament and increases the # of cross-bridges that may be formed for the same PCSA

Question 5

Type 2 myofilament are usually bigger. T/F

Answer 5

True

Question 6

PCSA calculation involves

Answer 6

Perpendicular to AOR of muscle
Muscle mass
Fiber length

Question 7

Muscle fiber and force production

Answer 7

May lose force at angle but can pack more force overall

Question 8

If you’re increasing size of muscles through hypertrophy, it’s also increasing contractile proteins. T/F

Answer 8

True

Question 9

Mitochondria will increase w/ hypertrophy. T/F

Answer 9

False!

Question 10

Mitochondria will increase with endurance training. T/F

Answer 10

True

Question 11

Will there still be mitochondria adaptation with endurance training and RT?

Answer 11

Yes

Question 12

What is the largest factor the determine’s one’s predominant muscle fiber distribution?

Answer 12

Genetics

Question 13

PRT may results in fiber type transformation from Type 2B to 2A. T/F

Answer 13

True

Question 14

Endurance training alters fiber type transition. T/F

Answer 14

False! No type 1 to 2 vice versa…

Question 15

Being immobilized can shift from Type 2A to 2B. T/F

Answer 15

True

Question 16

Around how weeks do neural and hypertrophy crosses over?

Answer 16

4-6 weeks

Question 17

Significant hypertrophy is seen after how many weeks?

Answer 17

6 weeks

Question 18

New stimulus to muscle can altar neural adaptations. T/F

Answer 18

True

Question 19

5 neural changes that improve strength!

Answer 19

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

Question 20

3 hypertrophic factors

Answer 20

1) hypertrophy
2) crease proportion area of type 2/ type 1 fibers
3) increase myofilament packing

Question 21

How much muscle mass increase compared to resting cals lost a day?

Answer 21

1 kg = 25 kcal/day

Question 22

Higher HR = Higher calories burned T/F

Answer 22

True

Question 23

EPOC

Answer 23

Oxygen consumption goes during exercise and in recovery from exhaustive exercise
High interval training

Question 24

How many calories do you expend for every liter of O2 consumed?

Answer 24

5

Question 25

We can’t get ATP in fast enough to use O2. T/F?

Answer 25

True

Question 26

The more well-trained you are the less lactate you build up and better clearance, less EPOC effect. T/F

Answer 26

True

Question 27

Muscle fiber types can’t be changed b/c

Answer 27

The innervation cannot be changed!! Nerves can be transposed. Unless surgery.

Question 28

M.fibers of type 1 have lower frequency so if it electrically gets stim with high frequency it can get change to type 2.

Answer 28

True

Question 29

RT in older adults will have 5-10% increase in strength after 4 weeks. T/F

Answer 29

True

Question 30

Training fast or slow velocity results in a different ability to generate force. T/F

Answer 30

True

Question 31

Training at fast velocities results in improvements only at high velocities. T/F

Answer 31

True

Baseball players

Question 32

Training at slow velocities improves across all speeds. T/F

Answer 32

True

Most people

Question 33

NM inhibition may be derive from (3)

Answer 33

1) unpleasant past experience
2) overly protective home environment
3) free of injury

Question 34

Are there neural adaptations in endurance trianing?

Answer 34

Yes, small amount

Question 35

As you train a contracted muscle will have less EMG activity during rest and increase during contraction. T/F

Answer 35

True

Question 36

Are there more EMG in eccentric or concentric?

Answer 36

Concentric

25% less in Eccentric, less neural innervation to hand the same load

Question 37

If EMG is higher and force production is higher

Answer 37

Neural adaptation taken place

Question 38

EMG same, force gets up

Answer 38

Due to hypertrophy!

Question 39

Can you use EMG to measure neural (strength changes) and hypertrophic factors?

Answer 39

Yes!!!