exercise intensity domains

Question 1

what is the gold standard protocol for VO2 max testing and exercise thresholds

Answer 1

ramp incremental test (RIT)

Question 2

what is the relationship between O2 measured from the mouth and PO

Answer 2

increase linearly

Question 3

what is mean response time (MRT)

Answer 3

delay in VO2 increase in relation to PO at the beginning of RIT
- PO increases while VO2 is stable for a few seconds

Question 4

what causes MRT

Answer 4

transit delay in physiological repsonses that need to occur at the beginning of exercise to meet muscle VO2 demand
- takes time for the level of O2 to go down in the musce and for the resp system to respond (transit time - values only measured at the mouth)

Question 5

how to account for MRT when prescribing exercise

Answer 5

PO difference produced by MRT should be subtracted from the ramp PO
(otherwise exercise intensity will be underestimated)

Question 6

which factors need to be considered in the moderate, heavy, and severe domains

Answer 6

moderate = MRT
heavy and severe = MRT and slow component

Question 7

what is the slow component

Answer 7

VO2 gradually goes up even at constant PO (drift in O2 uptake)
- as intensity increases, differences between VO2 and PO increases (increases dissociation)

Question 8

when does dissociation of VO2 in relation to RIT happen (slow component)

Answer 8

above GET - highest after RCP
(no slow component in moderate domain)

Question 9

what are the differences in constant load and RIT

Answer 9

higher VO2 in constant load/step
need to correct for slow component in RIT

Question 10

what are the reasons for the slow component (VO2 dissociation)

Answer 10

80% oxygen uptake in muscle during exercise
increased ATP turnover in muscle fibres

Question 11

why is there increased ATP turnover in muscle fibres

Answer 11

increased metabolic cost of fatiguing fibres
- tired muscle units = inefficient
- greater VO2 needed
- more energy needed for ion pumping

recruitment for more type II muscle fibres
- type II = less efficient than type I
- replacing fatigued type I fibres

Question 12

who has more or less slow component and why

Answer 12

women = less slow component
- have more type I muscle fibres therefore delayed recruitment of type II fibres

untrained = large slow component
- early recruitment of type II fibres

Question 13

how much dissociation of O2 uptake happens in moderate intensity domain

Answer 13

no dissociation

Question 14

how much dissociation of O2 uptake happens in heavy intensity domain

Answer 14

VO2 takes longer to stabilise and reaches values that are greater than predicted
- won’t reach VO2 max due to slow component

Question 15

how much dissociation of O2 uptake happens in severe intensity domain

Answer 15

VO2 gradually increases to VO2 max due to VO2 dissociation (drifts up)
only domain where this happens

Question 16

how much dissociation of O2 uptake happens in extreme intensity domain

Answer 16

• exhaustion occurs before VO2 max reached
• all exponential - no plateau in VO2

Question 17

why are thresholds important

Answer 17

prescribe exercise accurately
- same relative intesnity
- put individuals in the correct domain

predicts exercise performance
- determine the feasibility of a given task
- can predict how long people can go

Question 18

what is the exercise tolerance across the different domains

Answer 18

severe = seconds-45 mins
heavy = 45 mins-2 hours
moderate = >2 hours

Question 19

what is the variance in GET

Answer 19

40-80% of VO2max
typical = 60-65%
low end = untrained
high end = trained

Question 20

what is the variance in RCP

Answer 20

65-95% of VO2max
typical = 80%
low end = untrained
high end = highly trained

Question 21

can you shift the ratio between GET and RCP

Answer 21

yes
ex: 400m runner = high GET but low RCP % of VO2max

Question 22

what is the effect of slope of RIT on PO

Answer 22

at GET = very close (very small PO difference between slopes)
at RCP = large PO difference

way higher in larger slope
longer time = higher fatigue, can sustain less PO

Question 23

what is the effect of slope of RIT on VO2

Answer 23

no effect
same VO2 response at each threshold regardless of slope

Question 24

what is critical power

Answer 24

max rate of work that a muscle/muscle group can keep up with for a very long time without fatigue

greatest metabolic rate that results in only oxidative energy production

Question 25

what can critical power be used for

Answer 25

find RCP threshold without metabolic cart or lactate measures
- severe vs heavy domain

Question 26

how to find critical power

Answer 26

needs multiple sessiosn ot task failure
session 1 = very high intensity to failure
PO lowers with each session
can predict from PO curve

Question 27

what is W’

Answer 27

shape of hyperbolic curve
- area under the curve of the power v time graph (above critical power line)
amount of work that can be performed above critical power

Question 28

what does W’ predict

Answer 28

time to exhaustion in the severe intensity domain

Question 29

what is W’ correlated with

Answer 29

type II muscle fibres (above RCP)

no correlation with mito content and type I fibres

Question 30

what is W’ a measure of

Answer 30

exercise tolerance for intensities dependent on anaerobic metabolism (above critical power)

Question 31

what is critical power correlated with

Answer 31

elevates with increasing mito content and type I fibres

Question 32

what does the critical intensity of exercise separate

Answer 32

heavy and severe domain
above = unstable (exponential increase in VO2 and blood lactate)
below = metabolically stable

Question 33

how to find critical intensity

Answer 33

MLSS and CP