10. Adaptations in Endurance

Question 1

What is meant by the following terms

Tidal Volume

Vital capacity

Residual volume

Insipiratry reserve volume

Expiratory reserve volume

Answer 1

Tidal volume- Volume in a typical cycle of breathing

Vital capacity- Amount of lung voluem available for inspiration adn expiration

Residual volume- Constant volume of air in the lungs that cannot be removed

Inspiratory reserve volume- volume after a normal breath that allows for extra inspiration

Expiratory reserve volume- volume after a normal breath that allows for extra expiration

Question 2

What is the relationship between pulmonary ventilation and oxygen uptake in muscles

Answer 2

As ventilation increases so too does oxygen uptake

However this levels out at around 80-100% of maximum

Question 3

Is pulmonary ventilaiton a limitation in endurance exercise

Answer 3

No

Although increased oxygen partial presure can improve performance in highly trained athletes

However it is not a tfactor in lower trained individuals

Question 4

What is the relationship between respiratory function and V02 max

Answer 4

As vital capacity increases so too does VO2 max

Question 5

Explain the following terms

Cardiac cycle-

Stroke volume-

Ejection fraction-

Cardiac output-

Answer 5

Cardiac cycle- One cycle of the heart from systole to diastole

Stroke volume- Amount of blood pumped out by the left ventricle

Ejection fraction- % of blood pumped out of a filled ventricle

Cardiac output- The amount of blood put out by the heart at one time

Question 6

What is the equation for cardiac output?

Answer 6

Heart rate x Stroke volume = Cardiac output

Question 7

How does cardiac output change

Answer 7

At rest ~5L

During exercise 25-30L

Question 8

What are the mechanisms that alter heart rate during exercise?

Answer 8

Rest-100 BPM, decreased parasympathetic input

100- max, increased sympathetic input

Question 9

What factors alter Stroke volume change during exercise?

Answer 9

Increased venous return

Increased end- diastolic volume

Increased force of contraction

Frank-starling mechanism

Question 10

What is meant by the frank starling mechanism?

Answer 10

There is a length tension relationship in cardiac muscle with an optimum zone allowing for maximum output

Calcium also contributes to increasing cardiac output.
The more calcium the more the myocyctes are able to stretch and achieve maximum contraction

Question 11

How is increasd venous return achieved?

Answer 11

Sympathetic input to veins

Muscles pump veins

Respiration increases abdominal pressure and decreases thoracic pressure

Question 12

What causes increases in blood flow during exercise

Answer 12

Vasodilation of artierioles is stimulated by

Hydrogen
Lactate
Carbon dioxide
Potassium
Phosphate

Question 13

How does oxygen content change over time during exercise?

Answer 13

Arterial blood has a slight increase

Venous blood has a substantial decrease

This is due to oxygen being utilised by the muscle

Question 14

What variations are similairities in cardiac properties between elite athlertes and untrained individuals during exericse

Answer 14

maximal voluntary ventilation

Arterial oxygen capacity

Maximal HR

Arteriovenous difference

Question 15

Name the differneces in cardiac properties between elite athletes and untrained individuals duirng exercise

Answer 15

Maximal ocygen uptake

Maximal cardiac output

Stroke volume

Question 16

What are meant by the following terms?

Eccentric hypertrophy

Concentric hyperttrophy

Answer 16

Eccentric hypertrophy- Heart enlarges from the outside, leads to increased lumen

Concentric hypertrophy- heart enlarges from the inside, lumen stays the same

Question 17

What type of exercise affects the hearts growth?

Answer 17

Endurance exerccise- eccentric LVH

Static/isometric exercise- Concentric LVH

Question 18

What is the main adaptation of the heart in endurance exercise

Why is this beneficial?

Answer 18

Increased stroke volume

Greater ventricular filling and emptying leading to more blood pumped around the body

Question 19

Why does endurance training lower heart rate?

Answer 19

increased parasympathetic activity to the SA node

Increased stroke volume allows lower HR for any specified cardiac output

Question 20

How does endurance training affect coronary blood flow

Answer 20

Lack of data,

May cause increasde capillary density

Increased internal diameter of coronary arteries

Greater capacity for vasodilation