Aerobic Fitness Flashcards
(40 cards)
What are the 4 assumptions of sub-maximal fitness tests?
- there is a linear relationship between VO2, PO and HR
- Participants reach steady state at each stage
- Max heart rate at a given age is uniform
- Everyone has the same mechanical efficiency
Predictive tests are most useful for which population?
General population ! Athletes/ fit people are very limited by the HR and mechanical assumptions….sub-max tests can grossly underpredict VO2 max
Which test is the best submax test?
- Specificity
- Tests that actually bring people up to a higher intensity are better predictors of VO2 max (ie- lower intensity tests are lower predictors of VO2)
on average people score 10%higher on the treadmill than the bike for VO2 max…why?
- More muscles used therefore higher O2 demand
2. People who are not used to biking may experience muscle fatigue
VO2
volume of oxygen consumed
VO2 abs vs relative
what would we expect if someone is sitting at rest?
abs: L/min relative: ml/kg/min
divide 3.5 to get METS
VCO2
volume of expired CO2
RER
at rest?
as intensity increases
VCO2/VO2
when >1 , more CO2 being blown off than oxygen consumed
0.7 at rest
RER increases as intensity increases
what is someone is set up and right off the bat their RER is 0.9-1-above?
Is this a cause for concern
If we assume machine is set up properly and they set up their machine better
- they are hyperventilating
nerves, etc
- should go up as soon as exercise starts (VO2 increases right away as intensity increases)
If you see a high RER chances are you’ll see a high ?
HR
Vt ?
Tidal volume= normal breathing (how much air per breath)
normal= 0.5L
Ve?
Ventilation = frequence of breath x amount of breath (L/min)
What do we really look at to make sure the cart is set up? what are the normal values?
FeO2= fraction of O2 in expired gas = 16 FeCO2= fraction of CO2 in expired gas= 4
is the persons nose plug on???
How long should Direct tests last?
8-12 minutes
if less– too hard
if more — to long (fatigue biochemistry starts to set in)
Stages are typically how long for direct tests?
1-3 minutes (gotta hit steady state)
What is the peak criteria for direct tests?
- HR fails to increase with increasing workload or is close to age predicted max
- Blood lactate is >8mmol/L
- RER >1.15
- Volitional Fatigue (RPE> 17 on borg scale)
What is max criteria for direct tests?
Same as peak, but also must attain a plateau: <2ml/kgmin VO2 change with increasing workload
What percent of the population plateaus? Trained or untrained populations?
20%, mostly in trained because people are beasts and competitive
other people will get close to max and feel the volitional fatigue and quit
How do we determine threshold?
Anarobic threshold– cannot directly measure, can determine based on
- blood lactate values (lactate threshold)
- Ventilatory threshold
- RER=1 …will only last around one or two stages after (use RER live in lab)
How do you determine what % of VO2 max the threshold is at?
threshold value (RER=1)/ VO2max value X 100
60/73.9 =81%of VO2 max
Therefore his threshold is approx 81% of his VO2 max
Higher percent In trained people
Aerobic power?
Direct measure test= measure of aerobic power because there is a unit of time associated with it
Measures the functional ability of the CV system: measures the rate of O2 consumption
What is a measure of aerobic capacity?
Not direct measure !
You stay at a set workload and nothing changes and you just measure how long you can go for (takes forever)
how long your aerobic system can sustain you.
What does aerobic fitness represent?
the ability to perform dynamic exercise involving lasrge muscle groups at moderate to high intensity for prolonged periods
What is VO2 max? What does it depend on?
Maximal volume of O2 one can consume during exhaustive exercise
Depends on:
1. The transport of oxygen via the CV system to the working muscles
2. VO2= (HRxSV) x (a-vO2diff)
the ability of the muscles to delivery (Q) and to extract the oxygen (a-vO2 diff) at the muscle
