Strength

Question 1

How do our muscles get stronger?

Answer 1

Hypertrophy
Neural drive
Changes in muscle architecture
Changes in muscle fibre type
Hyperplasia

Question 2

What is hypertrophy?

Answer 2

• Only observable after 4 weeks of training
• Increase in muscle size can be explained by; an increase in myofibril thickness/ cross sectional area (CSA) - OR - an increase in number of myofibrils
• This increased thickness in induced by mechanical load placed on the muscle tissue
• Loading of muscle tissue; Induces muscle damage and upregulates protien synthesis

Question 3

How does hypertrophy occur?

Answer 3

Protein synthesis vs protein breakdown
Mechanical loading induces micro-damage/microtears which in-turn, increases protein synthesis

Question 4

How to influence hypertrophy?

Answer 4

Resistance training mainly induces an increase in CSA
Eccentric training has shown to increase in muscle length

Question 5

Endocrine/paracrine involvement in hypertrophy?

Answer 5

The various anabolic hormones secreted in response to mechanical loading mainly increase protein metabolism and upregulate satellite cell proliferation (for muscular repair)
- Important hormones to be aware of; Insulin-like growth factor: IGF-1
Testosterone
Growth hormone

Question 6

What is insulin-like growth factor: IGF-1?

Answer 6

• Increased protein synthesis
• Satellite cell proliferation and differentiation
• Satellite cell fusion to muscle fibres
• Increased calcium ion concentration

Question 7

What is testosterone?

Answer 7

• Increased protein synthesis
• Decreased rate of muscle breakdown
• Stimulates release of growth hormone
• Promotes satellite cell activation and replication

Question 8

What is growth hormone?

Answer 8

Has over 450 actions in 84 different cell types
Increased fat metabolism
Increases protein metabolism
Regulates immune function
Regulates bone modelling
Regulates extra-cellular fluid volume