Maximal Oxygen Uptake - In Lab Questions

Question 1

How does gender affect VO2max?

Answer 1

Men tend to have higher VO2max, usually due to:

• increased heart and lung size
• differences in levels of body fat

Question 2

How does genetics influence VO2 max?

Answer 2

• differing volumes of mitochondria

- VO2max is 50-95% due to genetics

Question 3

How does body size influence VO2max?

Answer 3

increased BMI = possibly poor respiratory capacity and CV endurance

Question 4

How does training status influence VO2max?

Answer 4

• endurance trained individuals have increase in VO2max by approx. 15%
• aerobically fit individuals have increased ability to thermoregulate

Question 5

How does environmental factors influence VO2max?

Answer 5

• 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)

Question 6

Do the lungs and ventilation limit VO2max?

Answer 6

yes they can

Question 7

What is the ventilation perfusion mismatch?

Answer 7

the disproportional increase in alveolar ventilation in comparison to perfusion with increasing intensity of physical activity

Question 8

What can happen with elite athletes with a greater cardiac output?

Answer 8

• 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

Question 9

you need more ____ for a given area of ___ at greater intensities of work

Answer 9

air; blood

Question 10

How do cardiac factors influence /limit VO2max? (with regards to O2)

Answer 10

-CO factors will determine the amount of O2 able to reach working muscles: more O2 = higher VO2

Question 11

Training increases the heart’s ability to pump more blood out, how does this affect VO2max?

Answer 11

increase in stroke volume means lower HR at same work rate as untrained person = better VO2max

Question 12

How does capilliary density change to affect VO2max?

Answer 12

density increases when body is at work - can train this (proliferation)

Question 13

How do mitochondrial changes influence VO2max?

Answer 13

mitochondria #/size/volume increase with training = more enzymes = better O2 consumption

Question 14

How does training influence EPO and affect VO2max?

Answer 14

training increases EPO which increases RBC production to have more Hb available to carry more O2 = increases VO2max

Question 15

Central factors that limit VO2max?

Answer 15

age (max HR)
level of training
genetics

Question 16

Peripheral Limiting factors of VO2max?

Answer 16

• mitochondria (mother genetics)

- fiber type distribution

Question 17

What muscle cell factors influence VO2max?

Answer 17

1. Increased [Mb-O2] = decrease in PO2 = increase in gradient - training increases myoglobin #’s
2. upregulation and relocation of mitochondria - training will change this
3. fiber type - training can shift this
4. temperature will change membrane fluidity
5. pH - with training you become more effective at buffering and removal of metabolic byproducts

Question 18

How does altitude affect VO2max?

Answer 18

increase in altitude = decrease in VO2max because less O2 is in air

Question 19

T/F: increase in lean mass = increase in VO2max

Answer 19

True

Question 20

“passage of blood through lungs for nutrient and O2 exchange”

Answer 20

perfusion

Question 21

“volume of air exchanged in lungs”

Answer 21

ventilation

Question 22

“when the exchange of air between the lungs and the environment does not equal the amount of blood reaching the capillaries in the lungs”

Answer 22

ventilation perfusion mismatch

Question 23

what is the most limiting factor for VO2max?

Answer 23

cardiac output - this is because peripheral factors consume oxygen faster than oxygen delivery

Question 24

increase in hemoglobin = inc or dec in o2 delivery?

Answer 24

increase = increase in vo2max

Question 25

how does an increase in myoglobin increase VO2max?

Answer 25

increases diffusion of O2 into muscle fibers/mitochondria

Question 26

how does pH affect VO2max?

Answer 26

more acidic = Hb drops O2 into blood plasma faster