Post-exercise metabolism

Question 1

What is oxygen deficit?

Answer 1

the difference between O2 requirement and O2 uptake at the onset of exercise.
- (Burnley & Jones, 2007)

Question 2

What is excess post-exercise oxygen consumption (EPOC)?

Answer 2

maintenance of O2 consumption levels above that which would be required for rest post-exercise

Question 3

Is EPOC affected by exercise intensity?

Answer 3

yas,
30 mins @ 70% vo2 max 
vs. 
20x1 min intervals @ 105%.
greater EPOC with higher intensity
- (LaForgia et al, 1997)

Question 4

What does respiratory exchange ratio (RER) tell us?

Answer 4

an indication of substrate mix

Question 5

What is the formula for RER?

Answer 5

VCO2 / VO2

Question 6

Under regular conditions, what is a typical RER?

Answer 6

~0.7-1

Question 7

What are some assumptions of RER?

Answer 7

> steady state conditions

>all CO2 produced and all O2 consumed is ‘metabolic’

Question 8

What is the name for the process in which muscle pH can drop from 7.0 to 6.4 and blood pH from 7.4 to 7.0 during intense exercise?

Answer 8

metabolic acidosis

Question 9

a) What values may RER reach during/immediately after intense exercise?
b) Why is this?

Answer 9

a) above 1

b) increased CO2 production

Question 10

What ‘non-metabolic’ process is responsible for the extra CO2 produced with intense exercise?

Answer 10

bicarbonate buffering.

prevents a large drop in pH but CO2 is a by-product

Question 11

Why is the CO2 produced through bicarbonate buffering considered ‘non-metabolic’?

Answer 11

it is not directly related to combustion of a substrate

Question 12

We’ve seen that RER can go above 1.

Can it go below 0.7?

Answer 12

yas

Question 13

When and how may RER fall below 0.7?

Answer 13

during recovery an RER of <0.7 is possible.
following metabolic acidosis and the associated bicarbonate buffering there’s an increased CO2 retention in order to replenish bicarbonate stores.
- (Metcalfe et al, 2015)

Question 14

How does plasma volume change with response to intense exercise and subsequently, following intense exercise?

Answer 14

plasma volume may drop with exercise due to fluid moving from intravascular space (i.e. in vessels).
following intense exercise, there may be a shift into intracellular space possibly due to build up of metabolic products

Question 15

How would you establish changes to plasma volume?

Answer 15

changes to haematocrit and haemoglobin

Question 16

How does exercise intensity affect plasma volume changes post-exercise?

Answer 16

higher intensity exercise results in greater plasma volume drop immediately post-exercise.
both high and low intensity groups recover blood plasma by 30-60 minutes post-exercise
- (Bloomer et al, 2103)
- (Metcalfe et al, 2015)

Question 17

When looking at changes to plasma glucose pre-during-post exercise, what must you do to the data to ensure consistency and accuracy of results?

Answer 17

correct for changes in plasma volume