neuromuscular adaptations

Question 1

The magnitude of the strength gain depends on?

Answer 1

the pre-training status of the subject

“detrained” have bigger strength gains

Question 2

Comparison of strength gains (Athlete vs detrained)

Answer 2

Athlete’s take 2x longer to see gains

Question 3

Isometric training leads to what kind of gains?

Answer 3

Leads to greater isometric strength not isokinetic strength

Question 4

isokinetic muscle action leads to what kind of gains?

Answer 4

Gains in muscular strength at the velocity most similar to the training

Question 5

Strength gains are maximized by?

Answer 5

matching the test and training modality

Question 6

men vs women strength gains?

Answer 6

same strength, body comp, etc (as long as background in similar)

Question 7

Myoplasticity

Answer 7

Muscle is highly changeable (adapts

Gene expression may alter protein quantity (amount) or quality (type)

Question 8

Hypertrophy is what kind of change?

Answer 8

Quantity- and increase in total amount of protein

Question 9

Type IIB —> Type IIA

Answer 9

Quality- a change in Myosin heavy chain protein

Question 10

Protein Turnover

Answer 10

Transcription (dNA to mRNA)
Translation (mRNA to protein)
Degradation (protein breakdown to amino acids)

Question 11

The level of a specific protein in the cell is governed by

Answer 11

Synthesis to degradation ratio (determines muscle size)

Question 12

Type II hypertrophy

Answer 12

an increase in rate of synthesis

Question 13

Type I hypertrophy

Answer 13

a decrease in degradation

Question 14

Resistance training

Answer 14

increases both types hypertrophy
type II (increase synthesis)
type I (decrease in degradation)

Question 15

4 influences on muscle protein expression

Answer 15

inadequate energy intake (decrease synthesis)
hormones (testosterone, grown horm.,insulin)
recruitment (adequate recruitment needed)
load (heavy load increase recruitment)

Question 16

What is hyperplasia?

Answer 16

increase in muscle cells leads to increased organ size

Question 17

What is Phenotype?

Answer 17

Structure

Question 18

Differences in fiber type response to resistance training?

Answer 18

Type II get stronger faster but both increase.

Synthesis increases hypertrophy faster than degradation

Question 19

men vs women and resistance training

Answer 19

Men increase muscle size more but % gains are similar

Question 20

Initial gains in strength are due to?

Answer 20

neural factors

Question 21

What is Specific Tension?

Answer 21

Force/cross sectional area (neurons/squared cm

Question 22

What is Cross education/cross training?

Answer 22

Resistance training one limb can lead to strength increases in the untrained limb on the contralateral side of the body.
Gains are less in the untrained limb
Only relates to the same muscle groups

Question 23

Ipsilateral and contralateral

Answer 23

Ipsilateral=same side

contralateral=opposite side

Question 24

mechanisms behind cross education

Answer 24

gains in contralateral side are neuromusclar (no muscle morphology)
Left & Right side of the motor cortex communicate during contraction

Question 25

Bilateral Deficit

Answer 25

Contracting both limbs simultaneously leads to decrease force development in each limb compared to independent contractions

Question 26

Methods of decreasing bilateral deficit

Answer 26

Training bilaterally leads to a reduction in deficit

Question 27

Decrease Coactivation of Antagonists

Answer 27

maximal contraction of one muscle group (biceps) leads to coactivation of antagonist (triceps)

Question 28

reductions of coactivation?

Answer 28

strength training reduces coactivation of antagonist leads to an increase in muscular strength expression

Question 29

4 indirect evidence of neural adaptation

Answer 29

1. change in specific tension (Increase) 2. Cross education 3. reduction of bilateral deficit 4. reduction of antagonist coactivation

Question 30

3 direct evidence of neural adaptations

Answer 30

1. increased neural drive 2. interpolated twitch 3. Alpha motor neuron excitability

Question 31

Increased neural drive

Answer 31

``` An increase in Activation from the brain to the muscles # of action potentials depend on (motor unit and firing rate) increased EMG signal=increased brain activity (increased motor unit activation) ```

Question 32

untrained individuals may not

Answer 32

be able to recruit Type II muscle fibers b/c they can't reach threshold

Question 33

Resistance training effect on neural drive

Answer 33

Increases EMG activity= increase in motor unit recruitment and firing rate

Question 34

Interpolated Twitch Technique

Answer 34

Stim unit can be placed on a maximally contracted muscle helps to determine if all motor units are activated. measures-extent of fully activated motor units

Question 35

Motor Neuron Excitability (Hoffman) H reflex

Answer 35

- Based on the Stretch reflex - affects primary 1a afferent - m-wave - orthodromic - antidromic

Question 36

M-wave

Answer 36

EMG resulting from a stimulated contraction

Question 37

Orthodromic

Answer 37

The normal direction of an action potential (away from cell body of neuron)

Question 38

Antidromic

Answer 38

Opposite direction (towards the alpha motor neuron) would not occur voluntarily

Question 39

Experimental setup of H reflex

Answer 39

- looks at changes in alpha motor neuron excitability - 1st done on astronauts (reflexes decrease in space) - plyometric ex. enhance reflexes

Question 40

Set up of experiment

Answer 40

stim unit on nerve (behind knee) >>bypass sensory system >> small stimulus = only 1a afferent w/o alpha motor neuron >> AP going to alpha motor neuron >>AP generated>>muscle contracts and H wave result of stimulation

Question 41

H reflex cont.

Answer 41

35ms from stimulus to hwave Increase stimulus leads to increased hwave limitation= mild stimulus can only be used b/c an mwave will be created with a high