Hypertrophy

Question 1

What is hypertrophy?

Answer 1

Increase in the number of size or cell in a tissue

Question 2

Contractile hypertrophy can occur by…

Answer 2

↑ Increase sarcomeres in series or in parallel

Question 3

What happens during hypertrophy?

Answer 3

Contractile elements enlarge

Question 4

What happens during hyperplasia?

Answer 4

Number of fibers within muscle increases

Question 5

Why do we need hypertrophy in contact sports?

Answer 5

For protection

To increase Impact forces

Question 6

What is the Pennation Angle

Answer 6

angle of the muscle fibers within the muscle with respect to the angle of force generation, also known as the line of pull.

Question 7

What is the degree of the Pennation Angle?

Answer 7

0º

Question 8

Fusiform

Answer 8

End to end

Question 9

Unipennate

Answer 9

Muscle fibers are oriented at one fiber angle to the force-generating axis

All on the same side of a tendon

Varies from 0º - 30º

Question 10

Bipennate

Answer 10

Muscles that have fibers on two sides of a tendon

Question 11

Multipennate

Answer 11

Fibers that are oriented at multiple angles along the force-generating axis

Question 12

Three mechanisms to attribute hypertrophy?

Answer 12

– Mechanical loading: Increased muscle tension

– Metabolic stress: Intramuscular energy depletion

– Muscle damage: Muscle fibre damage

Question 13

Mechanical & metabolic stresses cause growth signalling due to 3 different types of responses:

Answer 13

Muscle Contractions

Hormone Response

Immune Response

ALL 3 RESPONSES QWORK TOGETHER TO PROMOTE MUSCHLE GROWTH

Question 14

Exercise induced muscle hypertrophy facilitates 2 main “signalling pathways”

Answer 14

Protein Kinase pathway

Calcium Dependant pathway

Question 15

Protein Kinase pathway

Answer 15

Particularly sensitive to eccentric exercise (DOMS)

– Specific proteins linked to a rapid rise in cell proliferation/repair

Question 16

Calcium Dependant pathway

Answer 16

CDP’s linked to hypertrophy of ALL fiber types

– A lack of CDP’s shown to prevent muscle growth even if overload occurs

Question 17

Muscle damage

Answer 17

• Muscle fiber damage = by-product of resistance training & mechanical
loading/stress

• Inflammatory response
• Upregulation of muscle protein synthesis

Question 18

Muscle signalling

Answer 18

The primary driver of muscle hypertrophy in strength athletes is anincreased stimulation of myofibrillar protein synthesis .

Muscle Protein Synthesis > Muscle Protein Breakdown

Question 19

Hormones signal and promote growth by:

Answer 19

Growth Hormone (GH)

– Testosterone (TST)

– Insulin-like Growth Factor (IGF)

Question 20

Immune Response

Answer 20

•Mechanical stress à micro-trauma

• Immediate response from cytokines
– (umbrella term: cell signalling proteins)

• Neutrophil & Macrophage production:
– Neutrophil – circulating cells that are recruited by the blood to sites of inflammation
during acute bouts of exercise e.g: Resistance training
– Macrophage – found resting in the tissue. Once activated, they can secrete both
pro/anti-inflammatory cytokines

Question 21

Optimal stimulus for hypertrophy is?

Session per muscle group per week?

Answer 21

2-3 sessions per muscle group per
week

4-6 training sessions per week
• Alternatively 2 sessions per day of 30-45 mins
• Helps counteract catabolism if diet is correct

Question 22

Loading Parameters for Hypertrophy

Answer 22

Intensity 60-80% 1RM (up to 100%?)

Reps 8-12 RM

Sets 3-6

Rest Intervals 30-90 secs

Concentric Tempo 1-10 secs

Eccentric Tempo 4-10 secs

Total Set duration 20-70 secs

No of Ex’s per workout 3-6

No of Sets per workout 9-24

Question 23

Example Program – Legs

Answer 23

Lift/Exercise | Sets | Repetitions | Load | Rest

Back Squat 3 10 70% 1RM 60 seconds

Deadlift 3 10 70% 1RM 60 seconds

Split Squat 3 8 each leg 70% 1RM 60 seconds

Romanian Deadlift 3 10 70% 1RM 60 seconds

Leg Press 3 10 70% 1RM 60 seconds

Calf Raises 3 10 70% 1RM 60 seconds