6) Adaptations to Resistance Training Programs

Question 1

How do relative gains in strength compare between groups?

Answer 1

Relative gains in strength are similar when comparing different groups but the increase in absolute weight lifted varies between groups

Question 2

Gains in muscle size (?) are often paralleled by gains in ?

Answer 2

Gains in muscle size (hypertrophy) are often paralleled by gains in strength

Question 3

What is involved in muscle strength?

Answer 3

• Amount of force generated depends on the amount of actin and myosin and the number of cross-bridges formed within the sarcomere
• Involves neuroadaptations (increasing motor recruitment)
• and Size of muscle // amount of Actin/myosin cross-bridges possible

Question 4

Are increases in strength always observed as increased MM size?

Answer 4

No, Early in training, neuroadaptations are seen 1st
- Leads to increased strength without increase in size (ie no visible change)

However, Increases in MM size will always result in Increased strength

Question 5

? always accompany strength gains that result from resistance training but hypertrophy may or may not take place

Answer 5

Neural adaptations always accompany strength gains that result from resistance training but hypertrophy may or may not take place

Question 6

What are four ways in which the nervous system adapts to resistance training?

Answer 6

1. Synchronization and recruitment of additional motor units
2. Increased Rate Coding of motor units
3. Increased Neural Drive
4. Autogenic Inhibition

i) Synchronization and recruitment of additional motor units:
* Strength gains may result from increased synchronicity of motor units resulting in greater number of motor units firing at any one time, increasing force generation
* Controversy: does synchronicity increase force generated or rate of force development and capability to exert steady forces

ii) Increased rate coding of motor units:
* Increased neural drive to α-motor neurons increases frequency of discharge, or rate coding, of motor units
* Increases force or tension ie reach state of tetanic contraction

iii) Increased neural drive
* Neural drive is a combination of motor unit recruitment and rate coding of the units
* Neural drive starts in CNS and travels to muscles in peripheral nerves

iv) Autogenic inhibition
* Inhibitory mechanism to prevent muscles from exerting more force than bones and connective tissues can tolerate
* Golgi tendon organs: when the tension on a muscle’s tendons and internal connective tissue structures exceeds the threshold of Golgi tendon organs, motor neurons to that muscle are inhibited
* Resistance training can gradually reduce or counteract these inhibitory impulses; muscles can achieve a greater force production independent of increases in muscle mass

Question 7

Neural Control of Strength Gains

How does the neural adaption increase strength?
~Synchronization and Recruitment of Additional Motor Units ~

Answer 7

Synchronization and recruitment of additional motor units:
* Strength gains may result from increased synchronicity of motor units resulting in greater number of motor units firing at any one time, increasing force generation
* “Training Neurons to fire synchronously”
* Controversy as to whether its because of actual increas in force or from increased rate of recruitment

i) Synchronization and recruitment of additional motor units:
* Strength gains may result from increased synchronicity of motor units resulting in greater number of motor units firing at any one time, increasing force generation
* Controversy: does synchronicity increase force generated or rate of force development and capability to exert steady forces

ii) Increased rate coding of motor units:
* Increased neural drive to α-motor neurons increases frequency of discharge, or rate coding, of motor units
* Increases force or tension ie reach state of tetanic contraction

iii) Increased neural drive
* Neural drive is a combination of motor unit recruitment and rate coding of the units
* Neural drive starts in CNS and travels to muscles in peripheral nerves

iv) Autogenic inhibition
* Inhibitory mechanism to prevent muscles from exerting more force than bones and connective tissues can tolerate
* Golgi tendon organs: when the tension on a muscle’s tendons and internal connective tissue structures exceeds the threshold of Golgi tendon organs, motor neurons to that muscle are inhibited
* Resistance training can gradually reduce or counteract these inhibitory impulses; muscles can achieve a greater force production independent of increases in muscle mass

Question 8

How does the neural adaption increase strength?
Increased Rate Coding of Motor Units

Answer 8

Increased rate coding of motor units:
* Increased neural drive to α-motor neurons increases frequency of discharge, or rate coding, of motor units
* Increases force or tension ie reach state of tetanic contraction

i) Synchronization and recruitment of additional motor units:
* Strength gains may result from increased synchronicity of motor units resulting in greater number of motor units firing at any one time, increasing force generation
* Controversy: does synchronicity increase force generated or rate of force development and capability to exert steady forces

ii) Increased rate coding of motor units:
* Increased neural drive to α-motor neurons increases frequency of discharge, or rate coding, of motor units
* Increases force or tension ie reach state of tetanic contraction

iii) Increased neural drive
* Neural drive is a combination of motor unit recruitment and rate coding of the units
* Neural drive starts in CNS and travels to muscles in peripheral nerves

iv) Autogenic inhibition
* Inhibitory mechanism to prevent muscles from exerting more force than bones and connective tissues can tolerate
* Golgi tendon organs: when the tension on a muscle’s tendons and internal connective tissue structures exceeds the threshold of Golgi tendon organs, motor neurons to that muscle are inhibited
* Resistance training can gradually reduce or counteract these inhibitory impulses; muscles can achieve a greater force production independent of increases in muscle mass

Question 9

How does the neural adaption increase strength?
Increased neural drive
* Neural drive is a combination of ? and ?
* Neural drive starts in ? and travels to muscles in ?

Answer 9

Increased neural drive
* Neural drive is a combination of motor unit recruitment and rate coding of the units
* Neural drive starts in CNS and travels to muscles in peripheral nerves
* Results in stronger contraction
* Higher centres trained to stimulate faster and Recruit more

i) Synchronization and recruitment of additional motor units:
* Strength gains may result from increased synchronicity of motor units resulting in greater number of motor units firing at any one time, increasing force generation
* Controversy: does synchronicity increase force generated or rate of force development and capability to exert steady forces

ii) Increased rate coding of motor units:
* Increased neural drive to α-motor neurons increases frequency of discharge, or rate coding, of motor units
* Increases force or tension ie reach state of tetanic contraction

iii) Increased neural drive
* Neural drive is a combination of motor unit recruitment and rate coding of the units
* Neural drive starts in CNS and travels to muscles in peripheral nerves

iv) Autogenic inhibition
* Inhibitory mechanism to prevent muscles from exerting more force than bones and connective tissues can tolerate
* Golgi tendon organs: when the tension on a muscle’s tendons and internal connective tissue structures exceeds the threshold of Golgi tendon organs, motor neurons to that muscle are inhibited
* Resistance training can gradually reduce or counteract these inhibitory impulses; muscles can achieve a greater force production independent of increases in muscle mass

Question 10

How does the neural adaption increase strength?
Autogenic inhibition

Answer 10

Autogenic inhibition
* Inhibitory mechanism to prevent muscles from exerting more force than bones and connective tissues can tolerate
* Golgi tendon organs: when the tension on a muscle’s tendons and internal connective tissue structures exceeds the threshold of Golgi tendon organs, motor neurons to that muscle are inhibited
* Resistance training can gradually reduce or counteract these inhibitory impulses; muscles can achieve a greater force production independent of increases in muscle mass

i) Synchronization and recruitment of additional motor units:
* Strength gains may result from increased synchronicity of motor units resulting in greater number of motor units firing at any one time, increasing force generation
* Controversy: does synchronicity increase force generated or rate of force development and capability to exert steady forces

ii) Increased rate coding of motor units:
* Increased neural drive to α-motor neurons increases frequency of discharge, or rate coding, of motor units
* Increases force or tension ie reach state of tetanic contraction

iii) Increased neural drive
* Neural drive is a combination of motor unit recruitment and rate coding of the units
* Neural drive starts in CNS and travels to muscles in peripheral nerves

iv) Autogenic inhibition
* Inhibitory mechanism to prevent muscles from exerting more force than bones and connective tissues can tolerate
* Golgi tendon organs: when the tension on a muscle’s tendons and internal connective tissue structures exceeds the threshold of Golgi tendon organs, motor neurons to that muscle are inhibited
* Resistance training can gradually reduce or counteract these inhibitory impulses; muscles can achieve a greater force production independent of increases in muscle mass

Question 11

What are three factors affecting rate and total amount of gains of lean muscle mass?

Answer 11

Genetics
Age
Gender

Question 12

What is the Principle of Specificity?

Answer 12

Idea that there are certain training programs best-suited to individual goals
- “pick a program that benefits your goal”

Question 13

Hypertrophy vs Hyperplasia

Compare Hypertrophy and Hyperplasia:

Similarities // Differences

Answer 13

Both enlarge axial cross-sectional area of a muscle (Muscle gets bigger)

Fiber Hyperplasia:
- Increase in axial cross-sectional area of MM due to increases in number of muscle fibers (cells) per fascicle
- “Add more muscle cells (fibers) = bigger muscle”
- DEBATED - “it happens, we don’t know how”

Fiber Hypertrophy:
- Increase in axial-cross-sectional area of MM due to increases in size of pre-existing muscle fibers (cells)
- Make muscle bigger by increases the size of the muscle fibers that are already present

Question 14

Hypertrophy vs Hyperplasia

What is Hypertrophy

Answer 14

Fiber Hypertrophy:
- Increase in axial-cross-sectional area of MM due to increases in size of pre-existing muscle fibers (cells)
- Make muscle bigger by increases the size of the muscle fibers that are already present

Question 15

Hypertrophy vs Hyperplasia

What is Hyperplasia?

Answer 15

Fiber Hyperplasia:
- Increase in axial cross-sectional area of MM due to increases in number of muscle fibers (cells) per fascicle
- “Add more muscle cells (fibers) = bigger muscle”
- DEBATED - “it happens, we don’t know how”

Question 16

What is currently believed about Hypertrophy and Hyperplasia in humans?

Answer 16

Increased MM cross-sectional area primarily due to individual fiber hypertrophy

Hyperplasia is believed to be possible in humans
- Only very high intensity resistance training can result in fiber hyperplasia
- Percentage of total MM size increase due to hyperplasia is only ~ 5-10%

Question 17

What are two primary mechanisms of MM hyperplasia?

Answer 17

i) Fiber splitting
ii) Activation and Proliferation of satellite cells which fuse with each other to form new fiber

i) Fiber splitting
- observed in Cats; longitudinal split in muscle fibers in response to High resistance, Low Repititions (Performed wrist flexion against resistance for reward)

ii) Activation and Proliferation of satellite cells which fuse with each other to form new fiber
- Satellite cells are Myogenic stem cells
- Activated with sufficient mechanical stimulus (during injuring or increased mm loading/stretch)
- New Myoblastic Cells can
1) Fuse with existing MM fiber causing that fiber to get bigger (hypertrophy)
2) Fuse with each other to form a new fiber (hyperplasia)

Question 18

How does Fiber splitting result in hyperplasia?

Answer 18

Fiber splitting
- observed in Cats;
- longitudinal split in muscle fibers in response to High resistance, Low Repititions (Performed wrist flexion against resistance for reward)
- Unsure if this happens in humans

i) Fiber splitting
- observed in Cats; longitudinal split in muscle fibers in response to High resistance, Low Repititions (Performed wrist flexion against resistance for reward)

ii) Activation and Proliferation of satellite cells which fuse with each other to form new fiber
- Satellite cells are Myogenic stem cells
- Activated with sufficient mechanical stimulus (during injuring or increased mm loading/stretch)
- New Myoblastic Cells can
1) Fuse with existing MM fiber causing that fiber to get bigger (hypertrophy)
2) Fuse with each other to form a new fiber (hyperplasia)

Question 19

What is the role of Satellite cells in Hyperplasia?

Answer 19

Activation and Proliferation of satellite cells which fuse with each other to form new fiber (hyperplasia)
- Satellite cells are Myogenic stem cells
- Activated with sufficient mechanical stimulus (during injuring or increased mm loading/stretch)
- New Myoblastic Cells can
1) Fuse with each other to form a new fiber (hyperplasia)
2) Fuse with existing MM fiber causing that fiber to get bigger (hypertrophy)

Question 20

Satellite cells are ? stem cells
- Activated with sufficient ? stimulus
- New Myoblastic Cells can
1) Fuse with ? to ? (hyperplasia)
2) Fuse with ? to ? (hypertrophy)

Answer 20

• Satellite cells are Myogenic stem cells
• Activated with sufficient mechanical stimulus (during injuring or increased mm loading/stretch)
• New Myoblastic Cells can
  1) Fuse with each other to form a new fiber (hyperplasia)
  2) Fuse with existing MM fiber to increase size of that fiber (hypertrophy)

Question 21

Define:
i) Transient Hypertrophy
ii) Chronic Hypertrophy
iii) Sarcoplasmic Hypertrophy (SH)
iv) Myofibrillar Hypertrophy (MH)

Answer 21

Define:
i) Transient Hypertrophy
- Fluid accumulation (edema) in interstitial and EC spaces of mm immediately following a single bout of exercise
- Short // MM appear bigger for few hours MAX

ii) Chronic Hypertrophy
- Increase in MM size (axial-cross-sectional area) that occurs with long-term Resistance Training
- Eccentric Contraction results in greater hypertrophy and strength
- Two types: Sarcoplasmic and Myofibrillar

iii) Sarcoplasmic Hypertrophy (SH)
- type of Chronic hypertrophy
- Increase in sarcoplasm volume with constant sarcomere count (no change in protein)
- Increase in cellular components other than myofibrils (vol of mito // SR // T-tubules // Sarcoplasmic enzymes/substrate content)
- Favoured by Endurance resitance (Low weight; High Rep)

iv) Myofibrillar Hypertrophy (MH)
- Increase in number of sarcomeres in parallel at a constant sarcoplasmic volume
- More contractile proteins (actin and myosin)
- Favoured by Heavy-Load Resistance (High weight; Low rep)

Question 22

What type of Hypertrophy involves:
- Fluid accumulation (edema) in interstitial and EC spaces of mm immediately following a single bout of exercise
- Short // MM appear bigger for few hours MAX

Answer 22

Transient Hypertrophy
- Fluid accumulation (edema) in interstitial and EC spaces of mm immediately following a single bout of exercise
- Short // MM appear bigger for few hours MAX

ii) Chronic Hypertrophy
- Increase in MM size (axial-cross-sectional area) that occurs with long-term Resistance Training
- Eccentric Contraction results in greater hypertrophy and strength
- Two types: Sarcoplasmic and Myofibrillar

iii) Sarcoplasmic Hypertrophy (SH)
- type of Chronic hypertrophy
- Increase in sarcoplasm volume with constant sarcomere count (no change in protein)
- Increase in cellular components other than myofibrils (vol of mito // SR // T-tubules // Sarcoplasmic enzymes/substrate content)
- Favoured by Endurance resitance (Low weight; High Rep)

iv) Myofibrillar Hypertrophy (MH)
- Increase in number of sarcomeres in parallel at a constant sarcoplasmic volume
- More contractile proteins (actin and myosin)
- Favoured by Heavy-Load Resistance (High weight; Low rep)

Question 23

Transient Hypertrophy
- ? in interstitial and EC spaces of mm immediately following ?
- ?-lived

Answer 23

Transient Hypertrophy
- Fluid accumulation (edema) in interstitial and EC spaces of mm immediately following a single bout of exercise
- Short-lived // MM appear bigger for few hours MAX

ii) Chronic Hypertrophy
- Increase in MM size (axial-cross-sectional area) that occurs with long-term Resistance Training
- Eccentric Contraction results in greater hypertrophy and strength
- Two types: Sarcoplasmic and Myofibrillar

iii) Sarcoplasmic Hypertrophy (SH)
- type of Chronic hypertrophy
- Increase in sarcoplasm volume with constant sarcomere count (no change in protein)
- Increase in cellular components other than myofibrils (vol of mito // SR // T-tubules // Sarcoplasmic enzymes/substrate content)
- Favoured by Endurance resitance (Low weight; High Rep)

iv) Myofibrillar Hypertrophy (MH)
- Increase in number of sarcomeres in parallel at a constant sarcoplasmic volume
- More contractile proteins (actin and myosin)
- Favoured by Heavy-Load Resistance (High weight; Low rep)

Question 24

What type of Hypertrophy is being described?
- Increase in MM size (axial-cross-sectional area) that occurs with long-term Resistance Training
- Eccentric Contraction results in greater hypertrophy and strength
- Two types: Sarcoplasmic and Myofibrillar

Answer 24

Chronic Hypertrophy
- Increase in MM size (axial-cross-sectional area) that occurs with long-term Resistance Training
- Eccentric Contraction results in greater hypertrophy and strength
- Two types: Sarcoplasmic and Myofibrillar

Define:
i) Transient Hypertrophy
- Fluid accumulation (edema) in interstitial and EC spaces of mm immediately following a single bout of exercise
- Short // MM appear bigger for few hours MAX

iii) Sarcoplasmic Hypertrophy (SH)
- type of Chronic hypertrophy
- Increase in sarcoplasm volume with constant sarcomere count (no change in protein)
- Increase in cellular components other than myofibrils (vol of mito // SR // T-tubules // Sarcoplasmic enzymes/substrate content)
- Favoured by Endurance resitance (Low weight; High Rep)

iv) Myofibrillar Hypertrophy (MH)
- Increase in number of sarcomeres in parallel at a constant sarcoplasmic volume
- More contractile proteins (actin and myosin)
- Favoured by Heavy-Load Resistance (High weight; Low rep)

Question 25

Chronic Hypertrophy - Increase in MM size that occurs with **?** Training - **What type of Contraction** results in greater hypertrophy and strength - Two types: **?** and **?**

Answer 25

**Chronic Hypertrophy** - Increase in MM size (axial-cross-sectional area) that occurs with **long-term Resistance** Training - **Eccentric Contraction** results in greater hypertrophy and strength - Two types: **Sarcoplasmic** and **Myofibrillar** ## Footnote Define: i) Transient Hypertrophy - Fluid accumulation (edema) in interstitial and EC spaces of mm immediately following a single bout of exercise - Short // MM appear bigger for few hours MAX iii) Sarcoplasmic Hypertrophy (SH) - type of Chronic hypertrophy - Increase in sarcoplasm volume with constant sarcomere count (no change in protein) - Increase in cellular components other than myofibrils (vol of mito // SR // T-tubules // Sarcoplasmic enzymes/substrate content) - Favoured by Endurance resitance (Low weight; High Rep) iv) Myofibrillar Hypertrophy (MH) - Increase in number of sarcomeres in parallel at a constant sarcoplasmic volume - More contractile proteins (actin and myosin) - Favoured by Heavy-Load Resistance (High weight; Low rep)

Question 26

What are the two types of Chronic Hypertrophy?

Answer 26

i) **Sarcoplasmic Hypertrophy (SH)** - type of Chronic hypertrophy - Increase in sarcoplasm volume with constant sarcomere count (no change in protein) - Increase in cellular components other than myofibrils (vol of mito // SR // T-tubules // Sarcoplasmic enzymes/substrate content) - Favoured by Endurance resistance (Low weight; High Rep) ii) **Myofibrillar Hypertrophy (MH)** - Increase in number of sarcomeres in parallel at a constant sarcoplasmic volume - More contractile proteins (actin and myosin) - Favoured by Heavy-Load Resistance (High weight; Low rep) ## Footnote Define: i) Transient Hypertrophy - Fluid accumulation (edema) in interstitial and EC spaces of mm immediately following a single bout of exercise - Short // MM appear bigger for few hours MAX ii) Chronic Hypertrophy - Increase in MM size (axial-cross-sectional area) that occurs with long-term Resistance Training - Eccentric Contraction results in greater hypertrophy and strength - Two types: Sarcoplasmic and Myofibrillar iii) Sarcoplasmic Hypertrophy (SH) - type of Chronic hypertrophy - Increase in sarcoplasm volume with constant sarcomere count (no change in protein) - Increase in cellular components other than myofibrils (vol of mito // SR // T-tubules // Sarcoplasmic enzymes/substrate content) - Favoured by Endurance resistance (Low weight; High Rep) iv) Myofibrillar Hypertrophy (MH) - Increase in number of sarcomeres in parallel at a constant sarcoplasmic volume - More contractile proteins (actin and myosin) - Favoured by Heavy-Load Resistance (High weight; Low rep)

Question 27

What type of Hypertrophy is being described? - Is a subtype of Chronic hypertrophy - Increase in **sarcoplasm volume** with constant **sarcomere count** (no change in protein) - Increase in **cellular components** other than myofibrils (vol of mito // SR // T-tubules // Sarcoplasmic enzymes/substrate content) - Favoured by **Endurance resistance** Training (Low weight; High Rep)

Answer 27

**Sarcoplasmic Hypertrophy (SH)** - type of Chronic hypertrophy - Increase in sarcoplasm volume with constant sarcomere count (no change in protein) - Increase in cellular components other than myofibrils (vol of mito // SR // T-tubules // Sarcoplasmic enzymes/substrate content) - Favoured by Endurance resistance (Low weight; High Rep) ## Footnote Define: i) Transient Hypertrophy - Fluid accumulation (edema) in interstitial and EC spaces of mm immediately following a single bout of exercise - Short // MM appear bigger for few hours MAX ii) Chronic Hypertrophy - Increase in MM size (axial-cross-sectional area) that occurs with long-term Resistance Training - Eccentric Contraction results in greater hypertrophy and strength - Two types: Sarcoplasmic and Myofibrillar iv) Myofibrillar Hypertrophy (MH) - Increase in number of sarcomeres in parallel at a constant sarcoplasmic volume - More contractile proteins (actin and myosin) - Favoured by Heavy-Load Resistance (High weight; Low rep)

Question 28

Sarcoplasmic Hypertrophy (SH) - subtype of **?** - Increase in **?** with constant **?** (no change in protein) - Increase in **?** other than **?** (vol of mito // SR // T-tubules // Sarcoplasmic enzymes/substrate content) - Favoured by **?** Training (**?** weight; **?** Rep)

Answer 28

Sarcoplasmic Hypertrophy (SH) - subtype of **Chronic hypertrophy** - Increase in **sarcoplasm volume** with constant **sarcomere count** (no change in protein) - Increase in **cellular components** other than **myofibrils** (vol of mito // SR // T-tubules // Sarcoplasmic enzymes/substrate content) - Favoured by **Endurance resistance** Training (**Low** weight; **High** Rep) ## Footnote Define: i) Transient Hypertrophy - Fluid accumulation (edema) in interstitial and EC spaces of mm immediately following a single bout of exercise - Short // MM appear bigger for few hours MAX ii) Chronic Hypertrophy - Increase in MM size (axial-cross-sectional area) that occurs with long-term Resistance Training - Eccentric Contraction results in greater hypertrophy and strength - Two types: Sarcoplasmic and Myofibrillar iii) Sarcoplasmic Hypertrophy (SH) - type of Chronic hypertrophy - Increase in sarcoplasm volume with constant sarcomere count (no change in protein) - Increase in cellular components other than myofibrils (vol of mito // SR // T-tubules // Sarcoplasmic enzymes/substrate content) - Favoured by Endurance resistance (Low weight; High Rep) iv) Myofibrillar Hypertrophy (MH) - Increase in number of sarcomeres in parallel at a constant sarcoplasmic volume - More contractile proteins (actin and myosin) - Favoured by Heavy-Load Resistance (High weight; Low rep)

Question 29

Active Recall: Sarcoplasmic Hypertrophy

Answer 29

Sarcoplasmic Hypertrophy (SH) - subtype of **Chronic hypertrophy** - Increase in **sarcoplasm volume** with constant **sarcomere count** (no change in protein) - Increase in **cellular components** other than **myofibrils** (vol of mito // SR // T-tubules // Sarcoplasmic enzymes/substrate content) - Favoured by **Endurance resistance** Training (**Low** weight; **High** Rep)

Question 30

What type of Hypertrophy is being described: - subtype of Chronic hypertrophy - Increase in number of sarcomeres in parallel at a constant sarcoplasmic volume - More contractile proteins (actin and myosin) - Favoured by Heavy-Load Resistance (High weight; Low rep)

Answer 30

**Myofibrillar Hypertrophy (MH)** - Increase in number of sarcomeres in parallel at a constant sarcoplasmic volume - More contractile proteins (actin and myosin) - Favoured by Heavy-Load Resistance (High weight; Low rep) ## Footnote Define: i) Transient Hypertrophy - Fluid accumulation (edema) in interstitial and EC spaces of mm immediately following a single bout of exercise - Short // MM appear bigger for few hours MAX ii) Chronic Hypertrophy - Increase in MM size (axial-cross-sectional area) that occurs with long-term Resistance Training - Eccentric Contraction results in greater hypertrophy and strength - Two types: Sarcoplasmic and Myofibrillar iii) Sarcoplasmic Hypertrophy (SH) - type of Chronic hypertrophy - Increase in sarcoplasm volume with constant sarcomere count (no change in protein) - Increase in cellular components other than myofibrils (vol of mito // SR // T-tubules // Sarcoplasmic enzymes/substrate content) - Favoured by Endurance resistance (Low weight; High Rep)

Question 31

Myofibrillar Hypertrophy (MH) - Increase in **?** in **?parallel/series?** at a constant **?** - More **?** - Favoured by **?** Training (**?** weight; **?** rep)

Answer 31

Myofibrillar Hypertrophy (MH) - Increase in **number of sarcomeres** in **parallel** at a constant **sarcoplasmic volume** - More **contractile proteins** (actin and myosin) - Favoured by **Heavy-Load Resistance** Training (**High** weight; **Low** rep) ## Footnote Define: i) Transient Hypertrophy - Fluid accumulation (edema) in interstitial and EC spaces of mm immediately following a single bout of exercise - Short // MM appear bigger for few hours MAX ii) Chronic Hypertrophy - Increase in MM size (axial-cross-sectional area) that occurs with long-term Resistance Training - Eccentric Contraction results in greater hypertrophy and strength - Two types: Sarcoplasmic and Myofibrillar iii) Sarcoplasmic Hypertrophy (SH) - type of Chronic hypertrophy - Increase in sarcoplasm volume with constant sarcomere count (no change in protein) - Increase in cellular components other than myofibrils (vol of mito // SR // T-tubules // Sarcoplasmic enzymes/substrate content) - Favoured by Endurance resistance (Low weight; High Rep)

Question 32

What is the role of Sarcoplasmic Hypertrophy in the hypertrophic response to Resistance training?

Answer 32

- Sarcoplasmic Hypertrophy has a limited role in the hypertrophic response to resistance training - **Myofibrillar** hypertrophy accounts for majority of fiber growth - Hypothesis is that SH occurs first to make room for MH to occur Hypertrophic responses to standardized training program can vary widely (genetics) ## Footnote iii) Sarcoplasmic Hypertrophy (SH) - type of Chronic hypertrophy - Increase in sarcoplasm volume with constant sarcomere count (no change in protein) - Increase in cellular components other than myofibrils (vol of mito // SR // T-tubules // Sarcoplasmic enzymes/substrate content) - Favoured by Endurance resitance (Low weight; High Rep) iv) Myofibrillar Hypertrophy (MH) - Increase in number of sarcomeres in parallel at a constant sarcoplasmic volume - More contractile proteins (actin and myosin) - Favoured by Heavy-Load Resistance (High weight; Low rep)

Question 33

What type of hypertrophy accounts for the majority of fiber growth?

Answer 33

- **Myofibrillar** hypertrophy accounts for majority of fiber growth - Hypothesis is that SH occurs first to make room for MH to occur ## Footnote iii) Sarcoplasmic Hypertrophy (SH) - type of Chronic hypertrophy - Increase in sarcoplasm volume with constant sarcomere count (no change in protein) - Increase in cellular components other than myofibrils (vol of mito // SR // T-tubules // Sarcoplasmic enzymes/substrate content) - Favoured by Endurance resitance (Low weight; High Rep) iv) Myofibrillar Hypertrophy (MH) - Increase in number of sarcomeres in parallel at a constant sarcoplasmic volume - More contractile proteins (actin and myosin) - Favoured by Heavy-Load Resistance (High weight; Low rep)

Question 34

In Resistance Training: - Hypertrophy primarily results from:

Answer 34

In Resistance Training: - Hypertrophy primarily results from an **increase** in **sarcomeres** and **myofibrils** added in **parallel** (increase diameter rather than length)

Question 35

4 Steps to increase the size of a MM fiber: Pathway to hypertrophy: i) **?** stimulus skeletal MM ii) perturbations in **?** and related **?** // Microtrauma (damage to **?**) iii) ↑ size and amounts of **?**, ↑ in total number of **?** in **?** iv) ↑ **?** of individual fibers and ↑ muscle **?**

Answer 35

4 Steps to increase the size of a MM fiber: Pathway to hypertrophy: i) overload stimulus skeletal MM ii) perturbations in **myofibers** and related **ECM** // Microtrauma (damage to **sarcomere**) iii) ↑ size and amounts of **myofibrillar contractile proteins** actin and myosin, ↑ in total number of **sarcomeres** in **parallel** iv) ↑ **diameter** of individual fibers and ↑ muscle **cross-sectional area**

Question 36

# Muscle Hypertrophy Muscle cell repair: mediated by a balance between **?** and **?**

Answer 36

Muscle cell repair: mediated by a balance between **Muscle Protein Synthesis** and **degradation** ## Footnote Hypertrophy occurs when Protein Synthesis exceeds Protein Breakdown

Question 37

**?** occurs when Protein Synthesis exceeds Protein Breakdown

Answer 37

**Hypertrophy** occurs when Protein Synthesis exceeds Protein Breakdown

Question 38

What cell type mediates MM Hypertrophy? | MM: muscle

Answer 38

Satellite cells - New myoblastic cells fuse with existing MM fiber causing that fiber to get bigger (Hypertrophy) ## Footnote Role of satellite cells in hyperplasia: Satellite cells fuse with eachother to form a new fiber

Question 39

How do Satellite cells facilitate muscle hypertrophy?

Answer 39

Satellite cells facilitate muscle hypertrophy by donating extra nuclei to mm fibers, increasing synthesis of contractile proteins

Question 40

The role of Satellite cells in hypertrophy: New **?** cells can fuse with damaged but viable **?** to promote **?** Add ***?*** -> Increases synthesis of **?** - Myonuclear domains: - **?** regulates mRNA production for a finite **?** - Increases in fiber size must be accompanied by a proportional increase in **?** - Muscles have multiple **?**

Answer 40

New **myoblastic** cells can fuse with damaged but viable **myofibers** to promote **repair and regeneration** Add ***nuclei*** -> Increases synthesis of **contractile proteins** - Myonuclear domains: - **Myonucleus** regulates mRNA production for a finite **sarcoplasmic volume** - Increases in fiber size must be accompanied by a proportional increase in **myonuclei** (increase number or increase size) - Muscles have multiple **myonuclear domains** ## Footnote *Each Nuclei* can handle only a finite cell volume; as MM fiber size increases, requires more nuclei

Question 41

Three functions of satellite cell proliferation

Answer 41

1. Repair damaged myofibrils (fuse with and repair via protein synthesis) 2. Enlarge existing myofibers 3. Increase total fiber number (can fuse together to form new fiber (hyperplasia))

Question 42

# Muscle Hypertrophy Training → **?** (at cellular level // damage to **?** →**?** signaling → **?** activation → muscle **?**

Answer 42

Training → **microtrauma** (at cellular level // damage to **sarcomere** →**hormonal** signaling → **satellite cell** activation → muscle **protein synthesis**

Question 43

3 primary factors responsible for initiating the hypertrophic response to resistance exercise

Answer 43

3 primary factors responsible for initiating the hypertrophic response to resistance exercise: 1. Mechanical tension 2. Muscle damage 3. Metabolic stress ## Footnote Training must have a combination of these three to cause mm hypertrophy Factors such as genetics, age and gender will affect rate and total amount of gains of lean mm mass

Question 44

What is Mechanical Tension?

Answer 44

- Mechanically induced tension produced by both **force generation** and **stretch** - Essential to muscle growth - Additive ## Footnote - One of the three factors responsible for initiating the hypertrophic response to resistance exercise

Question 45

What is the impact of eccentric contractions on Mechanical Tension?

Answer 45

**Eccentric Contractions** cause passive muscular tension due to *lengthening* of extramyofibrillar elements (eg collagen content in ECM and titin) - Adds to active (contraction) tension developed by contractile elements (Actin and myosin) → ↑ Damage → ↑ Hypertrophy - Enhances hypertrophic response ## Footnote Mechanical Tension - One of the three factors responsible for *initiating the hypertrophic response* to resistance exercise - Mechanical overload increases mm mass - tension associated with resistance training* disturbs the integrity of skeletal mm* leading to **mechano-chemically** transduced **molecular** and **cellular** responses in myofibers and satellite cells

Question 46

Mechanical tension - Mechanical overload increases **?** - tension associated with **?** training *disturbs the integrity of skeletal mm* leading to **?** transduced molecular and cellular responses in **?** and **?**

Answer 46

- Mechanical overload increases **mm mass** - tension associated with **resistance** training *disturbs the integrity of skeletal mm* leading to **mechano-chemically** transduced molecular and cellular responses in **myofibers** and **satellite cells**

Question 47

What type(s) of contraction(s) cause MM damage resulting in hypertrophy?

Answer 47

- Caused by **eccentric**, **concentric**, and **isometric** contractions - **Eccentric**: cause the most damage to MM fibers -> activates satellite cells ## Footnote Muscle Damage - Hypertrophy - Resistance training can cause localized damage to MM tissue

Question 48

How does MM damage contribute to hypertrophy?

Answer 48

Repeated process of injuring fibers followed by **regeneration** may result in an overcompensation of **protein synthesis** resulting in a **net anabolic** effect ## Footnote MM damage is one of the three factors required for Hypertrophy Microtrauma (localized damage to MM tissue) → **neutrophils** migrate to damage → agents released (eg cytokines) attract **macrophages** and **lymphocytes** Macrophages - Remove cellular debris - Release cytokines → activate myoblasts, macrophages, lymphocytes - **Growth factors** are released that regulate satellite cell proliferation and differentiation

Question 49

# How does MM damage contribute to hypertrophy? **Microtrauma** (localized damage to MM tissue) → **?** migrate to damage → agents released by **?** (eg cytokines / Growth factors) attract **?** and **?**

Answer 49

**Microtrauma** (localized damage to MM tissue) → **neutrophils** migrate to damage → agents released by **damaged fibres** (eg cytokines) attract **macrophages** and **lymphocytes** ## Footnote Macrophages - Remove cellular debris - Release cytokines → activate myoblasts, macrophages, lymphocytes - **Growth factors** are released that regulate satellite cell proliferation and differentiation Repeated process of injuring fibers followed by **regeneration** may result in an overcompensation of **protein synthesis** resulting in a **net anabolic** effect

Question 50

What is the role of **macrophages** in muscle hypertrophy resulting from muscle damage? 1) Remove **?** 2) Release **?** 3) Activate **?**

Answer 50

Macrophages 1) Remove **cellular debris** 2) Release **cytokines** → activate **myoblasts**, **macrophages**, **lymphocytes** ## Footnote Microtrauma → neutrophils migrate to damage → agents released by damaged fibers attract macrophages and lymphocytes Macrophages - Remove cellular debris - Release cytokines → activate myoblasts, macrophages, lymphocytes - **Growth factors** are released that regulate satellite cell proliferation and differentiation Repeated process of injuring fibers followed by **regeneration** may result in an overcompensation of **protein synthesis** resulting in a **net anabolic** effect

Question 51

What is the role of growth factors released during Muscle Damage?

Answer 51

Growth factors *regulate* Satellite cell proliferation and differentiation

Question 52

What type of training causes build-up of metabolites resulting in Metabolic Stress?

Answer 52

High repetitions, low weight, low rest - Metabolite accumulation in muscle cells - Muscle Ischemia (↓ BF → ↑CO2 / ↑H+ / ↓O2) ## Footnote Metabolic stress * High repetitions, low weight training, low rest * Metabolite (ie. lactate, inorganic phosphate, ADP, hydrogen ions) accumulation in muscle cells Muscle ischemia: * Produces substantial metabolic stress and *potentially additive* to the hypertrophic effect when combined with glycolytic training * Induces alterations in hormonal milieu, cell swelling, free radical production, increased activity of growth-orientated transcription factors

Question 53

Effective hypertrophy-orientated resistance training should consist of a combination of **?** and **?**

Answer 53

Effective hypertrophy-orientated resistance training should consist of a combination of **mechanical tension** (Stress) and **metabolic stress** (environment changes) muscle damage

Question 54

# How does Metabolic stress contribute to MM hypertrophy? Metabolic stress **?type of exercise? (rep/weight/rest)** exercise causes build up of Metabolites (ie. **?**, **?**, **?**, **? ions**) in muscle cells

Answer 54

Metabolic stress High Rep, low weight, low rest exercise causes build up of Metabolites (ie. **lactate**, **inorganic phosphate**, **ADP**, **hydrogen ions**) in muscle cells ## Footnote Muscle ischemia: (↓ BF → ↑**CO2** / ↑**H+** / ↓**O2**) - Produces substantial metabolic stress and *potentially additive* to the hypertrophic effect when combined with **glycolytic** training - Induces alterations in **hormonal milieu**, cell **swelling**, **free radical** production, increased activity of growth-orientated **transcription factors** → Trigger **Satellite cells**

Question 55

# Metabolic stress and muscle hypertrophy Muscle ischemia: (↓ BF → ↑**?** / ↑**?** / ↓**?**) - Produces substantial metabolic stress and *potentially additive* to the hypertrophic effect when combined with **?** training

Answer 55

Muscle ischemia: (↓ BF → ↑**CO2** / ↑**H+** / ↓**O2**) - Produces substantial metabolic stress and *potentially additive* to the hypertrophic effect when combined with **glycolytic** training

Question 56

Metabolic stress induces alterations in * **?**, * cell **?**, * **?** production, * increased activity of **?** transcription factors → Trigger **?**

Answer 56

Metabolic stress induces alterations in * **hormonal milieu**, * cell **swelling**, * **free radical** production, * increased activity of **growth-orientated** transcription factors → Trigger **Satellite cells**

Question 57

**?** and **?** - upstream regulators of **anabolic** processes - Facilitate **protein** metabolism and subsequent **muscle growth** - Involved in **satellite** cell proliferation and differentiation - Facilitate binding of satellite cells to damaged fibers to aid in **muscular repair**

Answer 57

**Hormones** and **cytokines** - upstream regulators of **anabolic** processes - Facilitate **protein** metabolism and subsequent **muscle growth** - Involved in **satellite** cell proliferation and differentiation - Facilitate binding of satellite cells to damaged fibers to aid in **muscular repair**

Question 58

**Hormones** and **cytokines** - upstream regulators of **?** processes - Facilitate **?** metabolism and subsequent **?** - Involved in **?** cell proliferation and differentiation - Facilitate binding of satellite cells to damaged fibers to aid in **?**

Answer 58

**Hormones** and **cytokines** - upstream regulators of **anabolic** processes - Facilitate **protein** metabolism and subsequent **muscle growth** - Involved in **satellite** cell proliferation and differentiation - Facilitate binding of satellite cells to damaged fibers to aid in **muscular repair**

Question 59

What are three training methods to maximize muscle hypertrophy?

Answer 59

1. Agonist/Antagonist 2. High load Resistance training + low load blood flow restriction training 3. Accentuated eccentric training ## Footnote 3 training methods to maximize muscle hypertrophy: 1 Agonist/antagonist * Or upper/lower body supersets * Short rest periods and higher metabolic stress 2 High load resistance training + low load blood flow restriction training * Occlude venous return of blood from an extremity when training * Increases metabolic stress even at low loads 3 Accentuated eccentric training * Use a higher load on the eccentric portion of the exercise than on the concentric portion of the exercise * During eccentric contractions, passive muscular tension develops because of lengthening of extramyofibrillar elements ie collagen content in ECM and titin

Question 60

# 3 training methods to maximize muscle hypertrophy: What is Agonist/antagonist Training * **?** * Short **?** * higher **?**

Answer 60

1 Agonist/antagonist * Or **upper/lower body supersets** * Short **rest periods** * higher **metabolic stress** ## Footnote 3 training methods to maximize muscle hypertrophy: 1 Agonist/antagonist * Or upper/lower body supersets * Short rest periods and higher metabolic stress 2 High load resistance training + low load blood flow restriction training * Occlude venous return of blood from an extremity when training * Increases metabolic stress even at low loads 3 Accentuated eccentric training * Use a higher load on the eccentric portion of the exercise than on the concentric portion of the exercise * During eccentric contractions, passive muscular tension develops because of lengthening of extramyofibrillar elements ie collagen content in ECM and titin

Question 61

# 3 training methods to maximize muscle hypertrophy: What is "High load resistance training + low load blood flow restriction" training * Occlude **?** from an extremity when training * Which serves to Increase **?** even at low loads

Answer 61

High load resistance training + low load blood flow restriction" training * Occlude **venous return of blood (BF)** from an extremity when training * Which serves to Increase **metabolic stress** even at low loads ## Footnote 3 training methods to maximize muscle hypertrophy: 1 Agonist/antagonist * Or upper/lower body supersets * Short rest periods and higher metabolic stress 2 High load resistance training + low load blood flow restriction training * Occlude venous return of blood from an extremity when training * Increases metabolic stress even at low loads 3 Accentuated eccentric training * Use a higher load on the eccentric portion of the exercise than on the concentric portion of the exercise * During eccentric contractions, passive muscular tension develops because of lengthening of extramyofibrillar elements ie collagen content in ECM and titin

Question 62

# 3 training methods to maximize muscle hypertrophy: What is Agonist/antagonist Training * **?** * Short **?** * higher **?**

Answer 62

3 training methods to maximize muscle hypertrophy: 1 Agonist/antagonist * Or **upper/lower body supersets** * Short **rest periods** * higher **metabolic stress** ## Footnote 3 training methods to maximize muscle hypertrophy: 1 Agonist/antagonist * Or upper/lower body supersets * Short rest periods and higher metabolic stress 2 High load resistance training + low load blood flow restriction training * Occlude venous return of blood from an extremity when training * Increases metabolic stress even at low loads 3 Accentuated eccentric training * Use a higher load on the eccentric portion of the exercise than on the concentric portion of the exercise * During eccentric contractions, passive muscular tension develops because of lengthening of extramyofibrillar elements ie collagen content in ECM and titin

Question 63

# 3 training methods to maximize muscle hypertrophy: What is Accentuated eccentric training * Use a **?** on the eccentric portion of the exercise than on the concentric portion of the exercise * **?** eccentric contraction * During eccentric contractions, **?** develops because of *lengthening of extramyofibrillar elements* ie collagen content in ECM and titin

Answer 63

Accentuated eccentric training * Use a **higher load** on the eccentric portion of the exercise than on the concentric portion of the exercise * **Slower** eccentric contraction * During eccentric contractions, **passive muscular tension** develops because of *lengthening of extramyofibrillar elements* ie collagen content in ECM and titin ## Footnote 3 training methods to maximize muscle hypertrophy: 1 Agonist/antagonist * Or upper/lower body supersets * Short rest periods and higher metabolic stress 2 High load resistance training + low load blood flow restriction training * Occlude venous return of blood from an extremity when training * Increases metabolic stress even at low loads 3 Accentuated eccentric training * Use a higher load on the eccentric portion of the exercise than on the concentric portion of the exercise * During eccentric contractions, passive muscular tension develops because of lengthening of extramyofibrillar elements ie collagen content in ECM and titin