Exercise and altitude Flashcards
Do high speed movements benefit from high altitude?
Yes - The lower air density at altitude offers less resistance to high-speed
movement, and sprint performances are either not affected or are improved.
Does endurance performance benefit from high altitude?
No - performance demands that is more dependent on O2 delivery to muscle
What does Boyle’s Law tell us?
Gas volume inversely proportional to its pressure
e.g., at higher pressure, air starts to spread out (still same pressure of O2)
What does hypoxia mean?
Low PO2
What does normoxia mean?
Normal PO2
What does hyperoxia mean?
High PO2
What does hypoxaemia mean?
Low levels of blood O2
What is the effect of altitude on environmental and physiological variables?
Exposure to hypoxia directly results in a reduction in arterial oxygen pressure (PaO2).
This disruption in homeostasis triggers neuroendocrine responses that help regulate important adjustments in key physiological systems
Short-term adjustments to altitude - ventilation changes?
- Hyperventilation (chemoreceptors)
- Raises alveolar O2
- Lowers alveolar CO2
- Causes alkalosis and diuresis (HCO3-)
Short-term adjustments to altitude - CV changes?
Increased resting HR and Cardiac Output
Cold/dry air (reduced humidity), dehydration, UV light (sunstroke, blindness)
What is the immediate physiological response to altitude ?
Get in more O2 molecules
What happens to VO2max with increasing altitude?
Aerobic power is extremely reduced at high altitudes
What is the effect of high altitude on the HR response to maximal exercise?
- Cardiac strain is reduced
Lactate production also isn’t higher at altitude at max effort (lactate paradox) - Max HR response to exercise is attenuated at altitude
- Evidence that activation of parasympathetic nervous system limits maximal heart rate response to exercise at altitude.
What is the effect of altitude on the ventilatory response to sub-maximal exercise?
Increased ventilation for same workload
What is the difference in minute ventilation between acute and longer term response to altitude?
Minute ventilation increases more as a longer term response to altitude