Maximal Oxygen Uptake - In Lab Questions Flashcards
How does gender affect VO2max?
Men tend to have higher VO2max, usually due to:
- increased heart and lung size
- differences in levels of body fat
How does genetics influence VO2 max?
- differing volumes of mitochondria
- VO2max is 50-95% due to genetics
How does body size influence VO2max?
increased BMI = possibly poor respiratory capacity and CV endurance
How does training status influence VO2max?
- endurance trained individuals have increase in VO2max by approx. 15%
- aerobically fit individuals have increased ability to thermoregulate
How does environmental factors influence VO2max?
- high temperatures decrease max CO
- stroke volume is decreased due to vasodilation in cutaneous vessels which decreases central venous volume, as a result the body compensates by raising HR (doesn’t fully make up difference though)
Do the lungs and ventilation limit VO2max?
yes they can
What is the ventilation perfusion mismatch?
the disproportional increase in alveolar ventilation in comparison to perfusion with increasing intensity of physical activity
What can happen with elite athletes with a greater cardiac output?
- decreased transit time of the red blood cells in the pulmonary capillary will lead to insufficient time to saturate blood with O2
- blood is moving through lungs at greater volume and speed, doesn’t have time to fully saturate with O2
you need more ____ for a given area of ___ at greater intensities of work
air; blood
How do cardiac factors influence /limit VO2max? (with regards to O2)
-CO factors will determine the amount of O2 able to reach working muscles: more O2 = higher VO2
Training increases the heart’s ability to pump more blood out, how does this affect VO2max?
increase in stroke volume means lower HR at same work rate as untrained person = better VO2max
How does capilliary density change to affect VO2max?
density increases when body is at work - can train this (proliferation)
How do mitochondrial changes influence VO2max?
mitochondria #/size/volume increase with training = more enzymes = better O2 consumption
How does training influence EPO and affect VO2max?
training increases EPO which increases RBC production to have more Hb available to carry more O2 = increases VO2max
Central factors that limit VO2max?
age (max HR)
level of training
genetics
Peripheral Limiting factors of VO2max?
- mitochondria (mother genetics)
- fiber type distribution
What muscle cell factors influence VO2max?
- Increased [Mb-O2] = decrease in PO2 = increase in gradient - training increases myoglobin #’s
- upregulation and relocation of mitochondria - training will change this
- fiber type - training can shift this
- temperature will change membrane fluidity
- pH - with training you become more effective at buffering and removal of metabolic byproducts
How does altitude affect VO2max?
increase in altitude = decrease in VO2max because less O2 is in air
T/F: increase in lean mass = increase in VO2max
True
“passage of blood through lungs for nutrient and O2 exchange”
perfusion
“volume of air exchanged in lungs”
ventilation
“when the exchange of air between the lungs and the environment does not equal the amount of blood reaching the capillaries in the lungs”
ventilation perfusion mismatch
what is the most limiting factor for VO2max?
cardiac output - this is because peripheral factors consume oxygen faster than oxygen delivery
increase in hemoglobin = inc or dec in o2 delivery?
increase = increase in vo2max
