Week 8. Response to exercise

Question 1

What are the adrenergic effects on adipose?

Answer 1

• triggers release of fatty acids from adipose
• -> peaks at 65% VO2max
• increasingly important at end of exercise

Question 2

Why is insulin secretion inhibited by adrenaline during exercise?

Answer 2

• insulin increased glycogen synthesis which is antagonistic to the priorities of the body during exercise

Question 3

What pathway mobilises the adrenergic effects on glucose metabolism?

Answer 3

PKA dependent signalling pathway

Question 4

How does cortisol maintain blood glucose?

Answer 4

• protein degradation and slowed protein synthesis

Question 5

What does adrenaline to do blood supply?

Answer 5

• increases it to brain, muscle, heart

- decreases it to intestines and kidneys

Question 6

What enzyme catalysises the conversion of glycogen to glucose-1-phosphate?

Answer 6

Phosphorylase

Question 7

How does the muscle take in glucose without insulin during exercise?

Answer 7

An insulin independent pathway.

Increased AMP –> increased AMPK –> increased GLUT4 expression

Question 8

Rise in catheloamines is dependant on what?

Answer 8

• intensity of exercise
• level of training
• higher in untrained than trained

Question 9

Is exercise an anabolic or catabolic process?

Answer 9

Catabolic

Question 10

What are the adrenergic effects of exercise?

Answer 10

• increased motor cortex activity in brain
• increase in aerobic capacity from rest to 55%
• increase in adrenaline

Question 11

What is the role of the HPA axis in late exercise?

Answer 11

• releases cortisol –> maintains blood glucose

- -> mediated through nuclear receptor pathway

Question 12

What nutrient is used for energy at the beginning of exercise?

Answer 12

Carbohydrate.

Low intensity endurance exercise –>fatty acids

Question 13

What are the two types of stress response associated with exercise?

Answer 13

• direct, acts on specific tissue (endocrine factor), maintains blood glucose.
• hierarchal cascade, if overstimulated –> cortisol produced and loss of muscle mass

Question 14

Reduced insulin means reduced protein synthesis. Why is this useful?

Answer 14

Amino acids saved from protein synthesis can be used in gluconeogenesis.

Question 15

What are the adrenergic effects on glucose metabolism in the cell?

Answer 15

• reduces cell UPTAKE of glucose but increases UTILISATION of glucose

Question 16

What is glycogenolysis?

Answer 16

Mobilisation of carbohydrate stores used for energy metabolism

Question 17

What does the muscle and liver do with glucose -1 phosphate?

Answer 17

Muscle uses it for glycolysis (does NOT release into blood)

Liver released glucose into blood.

Question 18

What happens to GH secretion during exercise?

Answer 18

Big increase in GH secretion.

IGF1 levels don’t change