Altitude Flashcards
Altitude and inspired O2 relationship
inverse- higher 02 at lower altitude
Altitude classification
Death zone- 7,500+
Extreme- 5,500-7,00
High-Very high- 1500-5,500
Sea Level- <1500
Extreme Altitude Stressors
Hypoxia
Extreme Cold
Dehydration
UV radiation
Respiratory Responses to acute altitude exposure
-Hypoxic Ventilatory Response
-Respiraotry Alkalosis
Excretion of excessive bicarbonate ions
-Reduced blood buffering capacity
-Reduces exercise intensity where lactate accumulates
Work of breathing at altitude
- Airway resistance is lower - reduced pressure
- Hypoxic hyperventilation increases energy cost of breathing in activity
- Energy cost of breathing may interfere with energy supply to muscle
Pulmonary Adjustments to altitude
Hyperventilation
Compensatory respiratory alkalosis
Vasoconstriction- higher blood flow to lung and brain
maximal HR and VO2 relationship to altitude
Decreases with altitude (HR -42%)
Hypoxia effects >48h
HIF-I Activation
EPO increase
Hb increase
Hypoxia Adaptation >2weeks
HRmax increase
Mithocondrial density
Aerobic Enzymes
Dehydration Causes
Low water pressure
Hyperventilation
Fluid intake impaired
Higher diuresis
UV radiation
100% higher at 4,300m
Altitude on performance
Reductions in swim performance up to 6%
Slower run times at altitude
Pathologies
Acute Mountain Sickness AMS High Altitude Pulmonary Edema Retinopathy Polycythemia Neurological disorders Trauma/ Fractures
Acute Mountain sickness symptoms
Severe headache Nausea Fluid retension Dyspnoea rapid pulse Insomnia Constipation
Acute Mountain Sickness Treatment
Return to sea level
Supplemental O2
Acetazolamide
Development of mountain sickness
Pulmonary Oedema
cerebral Oedema
