Altitude

Partial pressure of oxygen in alveoli (PAO2) is ___ mmHg

105 mmHg

How many mmHg is partial pressure of oxygen in arterial blood (PaO2) in pulmonary diffusion at sea level?

100 mmhg

Why is PaO2 < PAO2?

• Diffusion is not 100% complete

• Some blood bypasses ventilated area of lungs (shunt)

T/F: Alveolar and arterial PO2 declines as altitude increases

True

Why does PO2 decline at high altitude?

1. Barometric pressure is lower at high altitude

2. % O2 in air does not change

T/F: Decrease in PaO2 (arterial blood) at high altitude

True

T/F: Decrease in O2 diffusion gradient blood to muscle at high altitude

True

T/F: Decrease in O2 delivery at high altitude

True

T/F: VO2 max decreases as altitude increases

True

Why does VO2 max decrease as altitude increases?

Due to drop in PaO2 (partial pressure of oxygen in arterial blood)

T/F: Resting VO2 is similar at high altitude

True

How much lower was VO2 max at summit of Mt. Everest?

75% lower

T/F: O2 cost of work is not different at submaximal exercise

True

Why does perception of effort increase at submaximal exercise?

Because at higher % VO2 max

T/F: Time to exhaustion is reduced at submaximal exercise

True

T/F: Altitude has no impact on events < 2 min (less)

True

T/F: Performance declines in events > 2 min (greater)

True

How much % did VO2 max increase in live-high train-low?

3%

How much % does hemoglobin content increase in live-high train-low?

7%

How many seconds does 3000 m time decrease?

6 sec

Can live-high train-low improve performance?

Yes