Lecture 11 Flashcards
Altitude (23 cards)
What are some Environmental Conditions at Altitude?
Lower Atmospheric Pressure: Less oxygen available.
Lower Air Temperature: Colder conditions.
Lower Humidity: More fluid loss through breathing.
Higher Solar Radiation: Increased UV exposure.
Barometric Pressure
Total pressure from all atmospheric gases on the body
Hypobaric, Hypoxia and Hypoxemia meaning
Hypobaric: Low atmospheric pressure
Hypoxia: Low oxygen in the air.
Hypoxemia: Low oxygen in the blood.
What are the immediate respiratory responses to altitude?
You breathe faster and deeper (hyperventilation) because of low oxygen.
Breathing more lowers CO₂, which makes your blood less acidic (alkalosis).
Your kidneys help fix this by making you pee more, which can cause dehydration.
Altitude Training Strategies
Live High Train High
Live High Train High
Positives
Increased red blood cells
Increased VO2max
Negatives
Can’t train as hard due to low oxygen
Dehydration
Poor sleep
Altitude Training Strategies
Live High Train Low
Live high = acclimate to low oxygen (↑ red blood cells)
Train low = keep training intensity high (not limited by low O₂)
Known to improve endurance performance
What are the main health risks of exercising at altitude?
Acute Mountain Sickness
Acute Mountain Sickness (AMS): Most unacclimatized people experience symptoms above 3000m.
Symptoms: Headache, nausea, dizziness, fatigue, insomnia, Cheynes-Stokes breathing.
What are the main health risks of exercising at altitude?
High-Altitude Pulmonary Edema
High-Altitude Pulmonary Edema (HAPE): Fluid flooding the lungs.
Symptoms: As with AMS, plus excess mucus in lungs, cough, pink frothy sputum, bluish skin color.
What are the main health risks of exercising at altitude?
High-Altitude Cerebral Edema
High-Altitude Cerebral Edema (HACE): Fluid flooding the brain.
Symptoms: As with AMS, plus staggered gait, impaired mental processing, loss of consciousness.
How are altitude illnesses treated?
Descend to lower altitude
Oxygen therapy
Acetazolamide – helps fix pH by removing excess bicarbonate
What % is Air in oxygen
Air is 20.93% Oxygen (sea level or top of everest)
What gets less at top of everest?
Barometric Pressure
What happens to air pressure and oxygen at altitude?
↓ Barometric pressure (Pb)
↓ Partial pressure of oxygen (PO₂)
Air still ~20.93% O₂, but lower Pb → lower PO₂ (e.g. 52 mmHg on Everest)
How does UV exposure change with altitude?
↑ Solar radiation (~4% per 300m)
Less atmosphere + snow reflection → ↑ UV exposure
What are the short-term cardiovascular responses to altitude?
↓ Plasma volume → ↑ hematocrit
↑ HR to maintain Q (cardiac output)
↑ Blood viscosity & BP
What changes occur in muscle structure/function at altitude?
↓ Muscle mass & cross-sectional area
↑ Capillary density
↓ Mitochondrial function & enzyme activity
What is acclimatisation and how long does it take?
Gradual adaptation to altitude stress
Takes 2–6 weeks
Add 1 week per 600m above 3,000m
Benefits lost within 1 month at sea level
What are HAPE and HACE?
High-Altitude Pulmonary Edema
High-Altitude Cerebral Edema
HAPE: fluid in lungs, cough, pink frothy sputum, blue skin
HACE: fluid in brain, confusion, poor balance, LOC
Is it common to get sunburnt in altitude?
Due to uv. Closer to sun as uv travels through less atmosphere
Cold Air?
Very dry = Dehydration
Hold less water
High altitude is deemed as?
Over 5500m
Cardiovascular Response Chain
Hypoxia
Reduced Plasma Volume
Reduced Stroke Volume
Increased Heart Rate
Increased Cardiac Output
Maintain po2
po2 stands for?
Partial Pressure of Oxygen
