CV Response to Exercise

Question 1

What are the main components that adapt to exercise training?

Answer 1

Increase in left ventricle volume
Increase in wall/septal thickness
HR
Q
Blood volume
Increase in oxygen delivery to the muscle

Question 2

How does the CV system adapt acutely to exercise?

Answer 2

1. Increase in oxygen delivery to working muscles.
2. Increase in blood flow to the muscle.
3. Vasoconstriction of blood vessel to low activity tissues.

Question 3

How does the CV system adapt chronically to exercise?

Answer 3

Increase in VO2max.
- Delivers for oxygen to active muscle mass.
- More effective delivery of oxygen during sub-maximal activity.

Question 4

What is the Fick equation?

Answer 4

VO2 = Q * (a-v) O2 difference

Question 5

What does (a-v) O2 difference represent?

Answer 5

The extent to which O2 is extracted as it passes through the body.
The greater the value the better adapted an individual is and therefore more efficient at extracting oxygen by the tissues

Question 6

How do we measure (a-v) O2 difference?

Answer 6

Vein punctured to extract sample.
Compare the difference between ppO2 in the artery and ppO2 in the vein.

Question 7

What makes power athletes heart stronger?

Answer 7

An increase in left ventricle muscle mass

Question 8

What makes endurance athletes better adapted to aerobic exercise?

Answer 8

Increase in stroke volume due to an increase in preload.

Question 9

What is concentric hypertrophy of the heart?

Answer 9

Increase in wall/septal thickness which increases afterload and decreases stroke volume.

Question 10

What is eccentric hypertrophy of the heart?

Answer 10

Increase in left ventricle volume which increases preload and stroke volume.

Question 11

What 4 factors control acute blood flow regulation?

Answer 11

Metabolic regulation
Pressure changes
Dilator substances
Sympathetic autonomic activity

Question 12

Why does training increase blood volume?

Answer 12

Increase in plasma proteins (albumin has an osmotic effect).
Increased water retention via kidneys

Question 13

What is the difference between preload and afterload?

Answer 13

Preload = the volume of blood in the ventricle before contraction (end-diastolic volume).
Afterload = pressure against which the ventricle muscle must contract (= blood pressure).

Question 14

Why does haematocrit slightly lower between pre and post-exercise blood volume?

Answer 14

Increases in plasma volume mean the proportion of RBC in the blood slightly lower in comparison to volume.