L10a, Muscle Adaptations to Strength Training

Question 1

What are the 3 factors that affect muscle size?

Answer 1

1. Correct stimulus
2. Nutrition
3. Hormonal status

Question 2

What are peripheral muscle adaptations?

Answer 2

Changes in:
1. Muscle size
2. Ratio of fibre types
3. Architecture of the muscle
4. Metabolic capacity

Question 3

What are the 5 theories of muscle hypertrophy?

Answer 3

1. Mechanical tension- The force applied of on the muscle is the primary stimulus
2. Muscle damage- Damage to muscle fibres leads to muscle repair and growth
3. Metabolic stress- Accumulation of metabolites creates high stress envn. and leads to muscle growth
4. Hormonal- Theory that an increase in anabolic hormones is a primary stimulus for muscle hypertrophy
5. Energy- Energy demand leads to increase in number and size of mitochondria which leads to an increase in muscle size and strength

Question 4

What is sarcoplasmic hypertrophy?

Answer 4

Making a muscle larger without adding myofibrillar proteins like actin and myosin

Question 5

What type of training targets sarcoplasmic hypertrophy?

Answer 5

High rep with short rest (high volume)

Question 6

What is myofibrillar hypertrophy?

Answer 6

Increasing the number and size of the myofibrils, the contractile units of the muscle

Question 7

What type of training targets myofibrillar hypertrophy?

Answer 7

Heavy weights and lower reps with longer rest periods

Question 8

What is a pennation angle?

Answer 8

The angle between a fascicles orientation and the tendon axis

Question 9

What is the equation for relative strength?

Answer 9

Relative strength= Absolute strength / Body weight

Question 10

What is a motor unit?

Answer 10

Motor unit= Motor neuron + All fibres

Question 11

True or false: A muscle fibre may be innervated by a single motor neuron but a single motor neuron may innervate many muscle fibres

Answer 11

True

Question 12

What is are the contraction time and oxidative capacity characteristics of type I, type IIA, and type IIX fibres?

Answer 12

• Type I: Slow, high
• Type IIA: Fast, high
• Type IIX: Very fast, low

Question 13

Resistance training leads to increase in motoneuron excitability which =?

Answer 13

Greater recruitment and lower threshold for recruitment

Question 14

The brain normally protects muscle by inhibiting high synchronization of large numbers of motor units. What happens with training?

Answer 14

There is a reduction in this inhibition

Question 15

Stimulus for intramuscular coordination is less task specific and more specific to?

Answer 15

Velocity and load

Question 16

Disinhibition: What are golgi tendon organs?

Answer 16

Sensory receptors that elicit a reflex inhibition of the muscle they supply when it undergoes excessive tension, either by shortening or passive stretching.

Question 17

Disinhibition: What are Renshaw cells?

Answer 17

Inhibitory connecting neurons found in the spinal cord that dampen the rate of discharge of alpha motor neurons thus preventing the muscular damage derived from tetanic contraction.

Question 18

Disinhibition: What are supraspinal inhibitory signals?

Answer 18

Conscious or unconscious inhibitory signals that come from the brain

Question 19

What do the Ib afferents from tendon organs do?

Answer 19

Contact inhibitory interneurons that decrease the activity of motor neurons innervating the same muscle