Week 8- exercise and altitude Flashcards
what does a decrease in air pressure result in?
improved performance
What does lower air density at altitude offer?
less resistance to high speed movement
What does lower PO2 result in?
poorer aerobic performance
What is Boyle’s law?
-gas volume is inversely proportional to its pressure
-altitude increases as pressure decreases
-airways contain 21% O2 but it is thinner at altitude and thicker at sea level
What happens to atmospheric pressure at altitude?
atmospheric pressure decreases
What is hypoxia?
low PO2 (altitude)
What is Normoxia?
normal PO2 (sea level)
What is hyperoxia?
high PO2
What is hypoxaemia?
low levels of oxygen in the blood
What does exposure to hypoxia directly result in?
the reduction of arterial oxygen pressure (PaO2)
What does the disruption in homeostasis trigger?
neuroendocrine responses that help to regulate important adjustments in key physiological systems
At what time at altitude do you become unconscious?
1 minute
What is the immediate response to altitude?
get more oxygen in
What ventilation changes occur at altitude?
-hyperventilation
-raises alveolar oxygen
-lowers alveolar cardon dioxide
-causes alkalosis and diuresis (HCO3)
What are the cardiovascular changes at altitude?
increased resting heart rate and cardiac output
What are the changes for ventilation at higher altitude?
increased ventilation
What happens to heart rate at altitude?
decreased
What happens to an individuals VO2max if they spend time at altitude?
increases
What does more oxygen in the blood improve?
oxygen extraction capacity = less reliance of central delivery
What is polycythemia due to?
increased erythropoietin(EPO)
What is the usually oxygen carrying capacity in the blood?
200ml
What are the effects of a decrease in plasma volume?
Helps the haemoglobin
What does hyperventilation cause?
alkalosis
What are the vascular/cellular changes at working at altitude?
-increased capillarisation
-increased myoglobin in the muscles
-increased aerobic enzymes
-increased lactate consumption and oxidation by active muscles