VO2 max Flashcards
Define maximal oxygen uptake
-if O2 requirement is > than maximal possible O2 consumption of an individual, the activity won’t be able to be performed
Describe how VO2max is determined
-Measurement of oxygen consumption with progressive challenges to the body allows for assessment of aerobic metabolic response
-steady state stage permits understanding of O2 & metabolic requirements per stage
- maximal amount of oxygen that can be consumed per unit
Direct VO2 test
Any test that measures expired gasses
Advantages - accurate /reliable/very informative
Disadvantages - costly/poor subject comfort
indirect VO2 test
A test that uses another variable to predict VO2 max (HR)
Linear relationship between HR and VO2
Advantages - practical/ low cost/low resources
disadvantages - not as accurate/ based on a set of assumptions
absolute VO2 max
Incorporating body weight supported exercise
relative VO2 max
More appropriate when measuring exercise requiring moving of one’s body
Describe & calculate VO2max using the Fick equation
Q= VO2/av-O2
avO2= CaO2-CvO2
Positive relationship between cardiac Output and VO2 Max
Arterial- mixed venous O2 Content difference
As metabolic demand increases working muscles extract more O2 increasing a-Vo2 difference
This can be affected by diffusion limitation at the muscle level
Central adjustments that occur during exercise
-HR,SV, blood volume, ventricle size
Peripheral adjustments that occur during exercise
Muscle blood flow, metabolic oxidative potential, capillary density, size and number of mitochondria
Metabolic limits
Factors that limit oxidative phosphorylation
Enzymes concentration
Mitochondrial factors
Type 1 muscles fibers
Oxygen supply
Limit oxygen transport
SV
Blood flow
Blood volume
Convert VO2max between relative and absolute.
Absolute = L/min
Relative =(body mass) divide ml/kg/min
*** watch for units L to ml is multiple by 1000
