Altitude & Exercise Flashcards
How is altitude defined?
The height of an object or point in relation to sea/ground level
1500m + (medicine)
What are the categories of altitude?
Low - 1250m
Moderate - 1250-3000
High - 3000-6000
Severe - 6000+
What is hypoxia?
an inadequate supply of oxygen to respiring tissue
What are the 3 main things that are experienced at high altitude
Decrease ambient temperature
^ solar radiation
decrease barometric pressure
What is pascal’s rule (1648)
the pressure is less the higher one goes because there is less mass pushing down on top
What is Daltons law?
total pressure exerted is equal to the sum of the partial pressures of all individual gases
What happens to atmospheric pressure at altitude?
Decreases
causes partial pressures to drop too
What is barometric pressure at sea level?
760mmHg
Partial pressure equation
fractional concentration x total gas pressure
eg 0.21 (O2) x 760 = 159 mmHg
What are hypoxic, Normoxic and Hyperoxic conditions
Hypoxic - low oxygen pressure
Normoxic - normal oxygen pressure
Hyperoxic - high oxygen presure
What is the oxygen cascade?
P02 decrease causing reduced oxygen uptake and delivery through-out body
oxygen saturation falls
How can performing at altitude effect short races
there is less friction on the athletes (less air molecules)
How much does VO2max decrease with altitude
1% every 100 metres of elevation (above 1500m)
What does hypobaric hypoxia do to minute ventilation?
decreases (over 8 hours)
What are the 3 types of altitude sickness?
Mild altitude sickness (AMS)
High altitude pulmonary oedema (HAPE)
High altitude cerebral oedema (HACE)
Symptoms of AMS (acute mountain sickness)
Headache
Nausea
Fatigue
What causes AMS, HAPE, HACE
ascending more than 500m in a day
exercising vigorously
when does HAPE develop
after 2-3 days above 2500m
Symptoms of HAPE
excess fluid in lungs
breathlessness
fever
What is HACE
very rarely above 3000m blood vessels in brain become damaged and fluid may leak
Symptoms of HACE
severe headache
vomiting, confusion, drowsiness
coma
What are immediate responses to altittude
Hyperventilation
Increased blood flow (^ resting systemic BP)
Long term responses to altitude
^ blood O2 carrying capacity
^ RBC conc & HB synthesis
EPO increase
