lab 2: vo2 max measuremnets Flashcards
why is using open circuit spirometry popular
non-invasive method that allows researchers and clinicians to measure and understand many important mechanisms within the cardio-pulmonary systems, as well as the body’s metabolism during exercise.
what are some examples of values obtained thru open circuit spirometry
breath-by-breath measures of oxygen consumption (VO2), carbon dioxide production (VCO2), and minute ventilation (VE).
are breath-by-breath measures of oxygen consumption (VO2), carbon dioxide production (VCO2), and minute ventilation (VE) directly measured from open circuit spirometry?
no its obtained by using raw data
The values obtained from the system are: inspired O2 and CO2 fractions (FIO2 and FICO2; %), expired O2 and CO2 fractions (FEO2 and FECO2; %), and minute ventilation (VE; L/min).
what is the goal in obtaining data like inspired O2 and CO2 fractions (FIO2 and
FICO2; %), expired O2 and CO2 fractions (FEO2 and FECO2; %), and minute ventilation (VE; L/min).
The goal in obtaining this data is to determine the very popular VO2max (or VO2peak) wherein a subject is asked to exercise until his/her oxygen consumption reaches a plateau or peak
what is vo2
subject is asked to exercise until his/her oxygen consumption reaches a plateau or peak
preferred method for establishing an individual’s aerobic capacity and assesses an individual’s ability to use the aerobic energy system.
what are some of the reasons you might use the results of VO2 max test
a coach might use the results from the VO2max test to develop a specific training program for an athlete,
use pre- and post-training VO2max test values to determine the effectiveness of aerobic training protocols on his/her athletes.
cardiologist may want to screen a patient post-surgery to ensure that they are ready to take part in a rehabilitation program.
what are 2 varibales of interest from the vo2 max test used alot for determining ones aerobic fitness levels
vo2 max/v02 peak
ventilatory threshold value
what is the v02max/vo2 peak value
simply the maximum or peak amount of oxygen an individual’s body can
use per minute (L/min). It is typically expressed relative to the individual’s body weight, in ml/kg/min.
what is the ventilatory threshold
The ventilatory threshold is the point in a VO2max test where pulmonary ventilation (VE) increases disproportionately relative to increases in oxygen consumption (i.e., marked increase in the VE/VO2 ratio)
what is the point called at which the pulm ventilation is no longer directly associated to the bodys oxygen requirements
veentilatory threshold
why do we reach ventilatory thresehold
This is thought to be caused by the CO2 released in the buffering of lactate. With increased intensity of exercise, there is an imbalance between lactate production and clearance. The excess lactate is buffered, with one of the by-products being CO2
The excess CO2 stimulates ventilation, therefore
increasing VE/VO2. It should also be noted that the VCO2/VO2 increases disproportionately at this point
what are some different ways to express VT
1) VO2 at VT as a % of the individual’s VO2max
i. e., VO2 at VT / VO2max * 100
2) As a heart rate (HR) when the VT occurred
3) As a speed, load, work rate or effort level when the VT occurred
true or false: oonce you reach VT you can no logner exercise
false, you can continue to erxercise for an extended period of time but will quickly lead to exhaustion
If the VO2max is seen as an individual’s upper limit for
aerobic exercise, then the VT determines BLANK
how much of that limit can effectively be used for a significant
amount of time (i.e., aerobic efficiency).
explain the vo2 max test
an 8-12 min graded exercise test used to assess aerobic fitness levels
why is the vo2 max test not less than 8 minutes
values not properly attained/ dont reach a max
why is v02 max not valid after 12 minutes
test is prematurely ended because of fatigue
what does it mean for a test to be “graded”
intensity increases over time, incrementally
speed, workload, incline etc
what are 4 factors that affect v02 max
age
sex
genetics
traininng
explain how age affects vo2 max
vo2 maxc decrases 1% per year after 25 years old
explain how sex affects vo2 max
females have lower vo2 max than men by 15-30 %
explain how genettics affect vo2 max
40% of results for vo2 max are pre determined by genetics
explain how training can affect vo2 max
vo2 max can increase by 5-20% if you aerobically train
what are some control factors before a vo2 tes
no caffience, alcohol or meals 3 hours prior
no smoking 3 hours prior
rested and motivated for teset
external motivation
what are the 5 vo2 max end criteria
1) RER greater or equal to 1.10
2) Max HR (220-age)
3) RPE greater or equal 17
4) subject wants to stop
5) vo2 plateau is reached (looked at after test end)
=VO2 MAX attended
if someone reaches their max HR, is a v02 peak or max made
peak
if someone reaches their max HR, or RER, is that a reason to stop the tes
no , main goal is to reach the PLATEAU
what is the values to know if you reached plateau (vo2 max)
change in vo2 across the last load/stage change less than or equal to 2 ml/kg/min
why can you use VT and VCo2 interchangebly
because VE will increaese proportionally to increase in VCO2 (beforee VT)
before VT what type of sources of energy are we workign
aerobic
after VT, what is the mai ntype of energy
anerboic and aerobic sources
why will VE and VCO2 no t be propriontal afteer VT
lactate buffering
what are the 2 most important variables attained from VT and V slope graph
1) VO2 at VT (reportted as percentage of vo2 max)
2) HR at VT
what does VO2 at VT (reportted as percentage of vo2 max) value indicate
indicates effiencey of aerobic system
what does HR at VT value indiciate
indicates sustainble HR
in untrained individuals, what is a normal value of vo2 at vt ration
between 45-65 percent
in trained individuals, what is a normal value of vo2 at vt ration
clsoer to 85%
why is interval training at HR above HR at VT
because you can train the system to push the VT to the right (delay the onset of lactate accumulation)
=increse performance
=increase aerboic efficiency
when do we use RQ
only valid during steady stage (aerobic only)
=indicates nutrient mixture catabolized for energy
(0.7 pure fat
1=pure carbs)
what is RER ration
gas exchange values alterd by other factors (ex: exercise)
=measure of subjects effort
what is the formula for oxygen consumption
see notes for details BUT
VO2 = (VI x FIO2) - (VE x FEO2)
what are all values in the date calibratiof got
STPD
standard temp pressure dry
what formula is used to determine volume of air inhaled
haldene transformationn
what is the formula for haldene transportation
VI = VE x (FEN2/FIN2)
see notes
in order to calcuate fraction of nitrogen inn exhaled/inhaled air, what must you do
compare it to FIO2 from data
ex:
FIN2 = 100 % - ( FIO2+FICO2)
what is the formula for RER
RER = vc02 (l.min)/vo2
what is the formula for VCO2
see notes
VCO2 = VE x (FECO2-FICO2)
