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
