Lecture 13 - Maximal oxygen uptake: determinants and limits Flashcards Preview

Muscle & Exercise Physiology > Lecture 13 - Maximal oxygen uptake: determinants and limits > Flashcards

Flashcards in Lecture 13 - Maximal oxygen uptake: determinants and limits Deck (18):
1

there is a linear relationship between the oxygen uptake and the

power output

2

what happens to VO2 max with ageing?

tends to go down

part is due to a genuine response to aging but most is reduced physical activity levels

3

what is the frailty threshold?

15-16 ml/kg/min

below here, you're starting to get in areas where its hard to do daily activities

4

What is the heritability of VO2 max?

shown to be a close correlation in monozygotic twinsthe

max heritability has been estimated at 51%

half genetics, half dependent on how physically active you are



5

What are the potential limitations to maximal VO2?

respiration

central circulation - haem concentation, CO

peripheral blood flow - peripheral density, vascularity

metabolism
- substrate delivery
muscle mass
[mitochondria]

6

In the leg, it has been shown that VO2 max can be limited by...

oxygen delivery

7

Muscle mitochondrial capacity exceeds _____ delivery in humans

oxygen

8

If you want to increase your VO2max via oxygen delivery, what can you do?

blood dope - take erythropoid and increase Haem mass

Increase CO Max - by doing endurance training

9

When may the respiratory system be a limiting factor for VO2max?

if you go to altitude, if you have pulmonary disease,

if you're a highly trained athlete that has high pulmonary blood flow it creates a diffusion limitation

but in most healthy subject pulmonary will not be a limiting factor

10

As you approach VO2max the ___ delivery does become limiting

oxygen delivery

11

What is acute hypervolemia?

increased maximal SV and CO

achieved by expanding blood volume in untrained.

not as effective in trained subjects as their blood volume is already expanded

12

people who have high VO2MAX, there are differences in not only stroke volume, but..

blood volume

inceraased albumen synthesis among genetics factors that can increase blood volume

13

For a small muscle mass, if you exercise it you can increase the CO enough to give it all the blood it wants.

But as soon as you increase the muscle mass you have to constrain the blood flow, why?

as you can't afford to give all the blood to the contracting muscle - you'd faint

14

the maximal cardiac output is a maximal value

Yes, you can increase it with training but its a maximal value that limits your capacity to..

deliver blood to contracting muscles

VO2 MAX

15

If the pericardium is cut, what happens?

higher CO and VO2Max

found in dog studies

16

a higher muscle capillary density can lead to a higher...

VO2max

17

What type of relationship is the VO2max and muscle diffusion capacity?

linear

18

What is the consensus on the major limiting factor in VO2max?

oxygen delivery

probably due to the maximal cardiac output

Decks in Muscle & Exercise Physiology Class (34):