What happens to partial pressure of oxygen as altitude increases
PPO2 DECREASES
what happens when partial pressure of oxygen decreases
there is a reduction in the diffusion gradient between the air and lungs, and the alveoli and blood
what happens to haemoglobin when partial pressure of oxygen decreases, and how does this effect the performer
Haemoglobin is not fully saturated with o2
-less o2 delivered to working muscles so there is an earlier onset of fatigue
-athlete releases anaerobic/lactate threshold sooner, decreasing performance in aerobic exercise
o2 availability at altitude
sea level- 100%
med altitude (1500m)- 84%
high (2400m)- 76%
very high (5500m)- 52%
Days of training required for performance at differing altitudes
1000-1200- 3-5days
2000-3000- 2weeks
3000m+ - 2+weeks
Define barometric pressure
the measurements of air pressure in the atmosphere
Define partial pressure of oxygen
portion of pressure exerted only by the oxygen molecules in the air
Define hypobaric environment
an environment with a low atmospheric pressure such as that of high altitude
Define hypoxia
a condition where the body is deprived of adequate oxygen supply at tissue level
define hypoxemia
low level of oxygen in the blood
What is a hypobaric / altitude chamber
A chamber used during high terrestrial altitude research or training to stimulate the effects of high altitude on the human body especially hypoxia and hypobaria
What is hypobaria
Low ambient air pressure
What happens to the rate of diffusion when partial pressure is reduced
The rate of diffusion decreases in the alveoli
What happens when the rate of diffusion decreases in the alveoli
Decreased saturation of haemoglobin
Decreased oxygen transportation to muscles
Reduces diffusion of oxygen into the muscle cell
Which athletes choose to train at altitude and why
Elite endurance athletes due to aerobic benefits
Why is altitude training used
To acclimatise players to the lowest level of oxygen available in the atmosphere
What is altitude acclimatisation
A process where the athletes gradually adapts to a change in their performance
What physiological changes take place at altitude
Low oxygen in the blood is detected by kidneys
Kidneys release erythropoietin
EPO travels to bone marrow this stimulates the production of red blood cells (erythripolesis)
Oxygen levels rise, erythropoietin decreases
Iron absorption boosted during hypoxia
Benefits of altitude training
erythropoietin increases red blood cells production
Increased oxygen transportation
Improved oxygen extraction in muscle cells
Breathing rate and ventilation stabilise but remain elevated compared to sea level
SV and Q reduce as oxygen transport Inceases
Physiological adaptations
Increased number of red blood cell mass
Increase concentration of haemoglobin
Increased levels of EPO
Increase blood viscosity
Increased capillarisation of blood vessels
Increased breathing frequency and TV
Enhanced oxygen transport
Increase in AVO2-diff
Greater myoglobin stores
Improved buffering capacity
Benefits of altitude training to sporting performance
Increased:
Delivery of oxygenated blood to working muscles
Oxygen carrying capacity
Dissociation or o2 from haemoglobin
AVO2 diff- greater extraction of O2 at working muscle’s
Performers vo2 max
Anaerobic threshold
Delays OBLA
allows oxygen to stay in aerobic zone
Preserve anaerobic stores
Disadvantages of altitude training
Cost and accessibility
Altitude sickness and fatigue
Difficult to train due to lack of oxygen
Individual variability - not everyone responds the same
Limited duration of benefits
Impact of exercising in the heat
Exercising in heat above what an athlete is used to can reduce performance, and cause illness
Dehydration
Reduces ability to thermoregulate (dissipate heat) so core temp will rise
