Endocrine response to resistance training

Question 1

Define endocrine

Answer 1

When the hormone enters general circulation and acts on target cells in another body part

Question 2

Define endocrine system

Answer 2

The collection of glands of an organism that secrete hormones directly into the circulatory system to be carried towards a distant target organ.

Question 3

Define hormones

Answer 3

A regulatory substance produced in an organism and transported in biological tissue and /or fluids to stimulate specific cell/tissue types into a specific action

Question 4

Define autocrine

Answer 4

When the hormone acts on the cell that produced it

Question 5

Define paracrine

Answer 5

When the hormone acts on the adjacent cells to the production cells.

Question 6

Some hormones are released only after being triggered by the action of a different hormone. Cortisol is an example of this. How is cortisol released?

Answer 6

The hypothalamus produces corticotropin releasing hormone (CRH) to the pituitary gland.
Pituitary gland produces ACTH which stimulates the adrenal gland to produce cortisol.

Question 7

What helps control the pituitary’s production of ACTH?

Answer 7

Cortisol levels in the adrenal gland

Question 8

What are the 3 types of hormones and what are they made of?

Answer 8

Steroid - cholestral
Peptide - proteins
Amine - proteins

Question 9

How do steroidal hormones work?

Answer 9

• Steroid hormone enters cell
• Binds to specific receptor in the cytoplasm or nucleus
• Hormone-receptor complex activates the cells DNA forming mRNA
• mRNA leaves nucleus
• mRNA directs protein synthesis in the cytoplasm

Question 10

How do non-steroidal hormones work?

Answer 10

• The hormone binds to a specific receptor on the cell membrane (can’t pass through membrane)
• This activates adenylate cyclase within the cell and forms cAMP
• The cAMP activates protein kinases that lead to cellular changes and hormonal effects.

Question 11

What is the difference in the release of steroid hormones and peptides and amines?

Answer 11

Steroid - released as soon as produced

Peptides/amines - produced in advance and stored in vesicles for later release

Question 12

How does hormonal action interact with the lock and key theory?

Answer 12

Transport hormones, deliver hormone to receptor and protect from early metabolism

Question 13

List 2 systematic changes in hormone delivery with exercise?

Answer 13

• Fluid volume shifts

- Blood flow re-distribution during exercise - greater amount of hormones to working muscles

Question 14

How does an increased cardiac output effect hormone delivery?

Answer 14

Clearance of hormones through other tissues allows quicker delivery to muscle tissue.

Question 15

Which hormones have a response before resistance exercise?

Answer 15

Adrenaline

Noradrenaline

Question 16

Which hormones have a response during resistance exercise?

Answer 16

Adrenaline
Noradrenaline
Growth hormone
Testosterone

Question 17

Which hormones have a response after exercise?

Answer 17

Growth hormone
Testosterone
IGF-1
Insulin

Question 18

Where do males produce 95% of testosterone? and 5% of it?

Answer 18

95% from Leydig cells in testes

5% from adrenals

Question 19

Where do females produce lower concentration of testosterone from?

Answer 19

Ovaries and adrenals

Question 20

How long does steroidogenisis take?q

Answer 20

35 minutes

Question 21

How does testosterone work?

Answer 21

• passively diffuses across sarcolemma of a muscle fibre
• Binds with its receptor to form a hormone receptor complex (H-RC)
• H-RC arrives at genetic material in the cells nucleus and opens to expose transriptional units.

Question 22

What are the basal testosterone levels of males and females?

Answer 22

Males = 10-35 nmol.l
Females = <3.5 nmol.l

Question 23

What happens to serum testosterone with acute exercise?

Answer 23

It increases

Question 24

What are the 3 acute effect of testosterone on muscle tissue?

Answer 24

• Stimulates production of neurotransmitters
• Facilitates calcium release
• Increases protein synthesis

Question 25

Where is growth hormone secreted?

Answer 25

The pituitary gland

Question 26

What 4 target tissues does GH interact with?

Answer 26

• Immune cells
• bone
• fat cells
• muscle

Question 27

GH stimulates the liver to make what?

Answer 27

IGF

Question 28

When is the highest secretion of GH?

Answer 28

During sleep

Question 29

In women how do GH concentrations vary?

Answer 29

With menstrual phase

Question 30

What does acute GH response of exercise depend on?

Answer 30

load, rest and volume of exercise

Question 31

What is GH stimulated by during exercise?

Answer 31

Increase blood lactate

Question 32

Why do concentrations of GH peak after exercise?

Answer 32

Tissue repair roles

Question 33

Are there any differences in resting GH concentrations between trained and untrained individuals?

Answer 33

NO

Question 34

Where is insulin-like Growth Factors secreted?

Answer 34

By the liver and muscle produces own IGF

Question 35

List 5 effects IGF-1 has on the body?

Answer 35

• Increases glucose use
• Increases glycogen synthesis
• Increases protein synthesis
• Decreases lypolysis
• Increases collagen synthesis

Question 36

If basal concentrations of IGF-1 are low, what happens when training?

Answer 36

IGF-1 increases

Question 37

If basal concentration of IGF-1 are high, what happens to the levels when training?

Answer 37

No changes

Question 38

What type of exercise is a potent IGF stimulant?

Answer 38

Eccentric exercise

Question 39

How might chronic increases in testosterone potentially by unhealthy?

Answer 39

Leads to increase in LDL cholestrol

Question 40

What does recent data suggest in terms of actue responses of ‘anabolic hormones’ to resistance training and hypertrophy?

Answer 40

Suggests that ‘anabolic hormones’ acute response to resistance training are not necessary for hypertrophy and do not dictate gains in muscle mass and strength with resistance exercise