3. Maximum Oxygen Uptake: Limitations and Measurement

Question 1

What is Maximum Oxygen Uptake

Answer 1

The maximum rate at which oxygen can be taken up and utilised by the body during exercise, while breathing air at sea level.
VO2max
Measure of cardiorespiratory / aerobic fitness

Question 2

The Fick Equation

Answer 2

VO2 = Q x (a-v)O2 difference

Question 3

Absolute (independent of body mass) unit of measurement

Answer 3

l∙min-1

Question 4

Relative (standardised for body mass) unit of measurement

Answer 4

ml∙kg-1∙min-1
– Must be used if comparison between individuals is required
– Or comparison within an individual over a long period during which weight may significantly change

Question 5

Limitations to Maximum Oxygen Uptake

Answer 5

“Central” factors:
– maximal cardiac output
– the pulmonary diffusing capacity
– oxygen carrying capacity of the blood
“Peripheral” factor:
– skeletal muscle characteristics

Question 6

Limitations to Maximum Oxygen Uptake (3 points)

Answer 6

1* Impairment of any component of cardiorespiratory system reduces VO2max and aerobic exercise performance.
2patients suffering from heart disease (eg, heart failure), pumping function of heart may represent major limiting factor.
3 In respiratory diseases (eg. chronic pulmonary obstructive disease), ventilatory function is likely limited.

Question 7

Direct Measurement of V02max

Answer 7

exercise at a steadily
increasing work rate

Question 8

Submaximal Prediction of V02maxis based on…

Answer 8

Based on linear relationship between heart rate and oxygen uptake.
* Submaximal prediction from steady state heart rate at one or several work rates.

Question 9

effect of more training on delivery 02

Answer 9

With training, more O2 can be delivered to & used by active muscles.