Lecture 30: Circulatory Adaptations to Exercise Training

Question 1

What is the equation for VO2 max?

Answer 1

VO2max = CO * AVO2 difference

Question 2

What is a standard cardiac output value for an endurance athlete?

Answer 2

3.9 L.min

Question 3

What is a standard A-VO2 difference value for an endurance athlete?

Answer 3

160 ml.L

Question 4

What are the peripheral adaptations to aerobic training?

Answer 4

Increased flow to non-exercising muscles 
Increased muscle blood flow 
Greater haemoglobin affinity 
Increased vascular conductance 
Increased capillary density 
Oxygen diffusion 
Oxygen extraction

Question 5

What is the equation for MAP?

Answer 5

MAP = CO * TPR

Question 6

What happens to TPR when cardiac output increases?

Answer 6

It falls to accomodate for increased cardiac output

Question 7

What is a conduit artery?

Answer 7

An elastic artery

Question 8

What effect does exercise training have on conduit arteries?

Answer 8

It causes them to increase in distensibility (diameter)

Question 9

How did conduit artery diameter differ between dominant and non-dominant limbs?

Answer 9

Non-dominant limb had greater distensibility at any given blood pressure

Question 10

How did conduit artery diameter differ between trained and non-trained athletes?

Answer 10

Distensibility at higher blood pressures

Question 11

What is conductance?

Answer 11

The ability of a vessel to vasodilate

Question 12

What effect does training have on resistance arteries?

Answer 12

Increased conductance

Question 13

What is a resistance artery?

Answer 13

Found in the microcirculation

Provides a lot of resistance to flow

Question 14

What is the overall effect of training on conduit and resistance arteries?

Answer 14

Expansion of conduit arteries
Increased number of resistance arteries
Increased distensibility of conduit arteries
Increased conductibility of resistance arteries

Question 15

What two ways can we stimulate vasodilation in order to measure conductance?

Answer 15

Acetylcholine injection

Cuff pressure = metabolite build up

Question 16

What did the injection of acetylcholine show about young and old people’s conductance?

Answer 16

Young people have greater conductance

Old people have greater conductance after an aerobic training program

Question 17

What is angiogenesis?

Answer 17

Growth of new blood vessels

Question 18

What are the functional advantages of increased capillary supply?

Answer 18

Increased transit time (more complex nature of capillaries)

Lower diffusion distance

Question 19

What effect did exercise have on capillary tortuosity and density?

Answer 19

Increased both

Question 20

What effect did aerobic training have on blood flow and A-VO2 difference during sub-maximal and maximal exercise?

Answer 20

Sub-max: After training there was lower blood flow due to increased A-VO2
Max: After training both blood flow and A-VO2 difference increased

Question 21

What are the peripheral metabolic changes that cause increased O2 consumption, due to exercise?

Answer 21

Increased mitochondria

Increased oxidative enzymes

Question 22

What are the peripheral vascular adaptations to exercise?

Answer 22

Increased artery diameter
Increased artery conductance
Increased vasodilatory regulation of vascular tone
Increased number of arteries

Increased number of capillaries
Increased transit time
Decreased diffusion distance

Question 23

What is the effect of regular aerobic training on oxygen extraction?

Answer 23

Increased A-VO2 difference

Question 24

What effect does aerobic training have on the coronary vascalurture?

Answer 24

Increased capillarisation (due to cardiac hypertrophy)
Increased coronary artery diameter
Increased collateral blood flow

Question 25

Discuss blood flow to the splanchnic region after aerobic training.

Answer 25

It increases

This means there is potential for more blood flow to muscles due to greater vasoconstriction

Question 26

Discuss the effect of endurance training on blood flow to the cutaneous system with increasing heat stress.

Answer 26

No change in temperature threshold
Increased blood flow to the skin after threshold is met
This causes better heat loss

Question 27

What are the inducers of vascular remodelling?

Answer 27

Metabolic:

Inducing hypoxia during training causes a long-term increase in blood flow
Hypoxia causes increased VEGF secretion

Mechanical:

Increased blood flow - Increased sheer stress - Increased NO production - NO production stimulates growth - Current level of shear stress becomes normalised - Increased potential for more NO production

Growth Hormones:

VEGF stimulate growth of vascular tissue that increases ability to vasodilate