Exercise at altitude Flashcards
Altitude defintion
The height or elevation of an area above sea level
As altitude increases the ____________ ____________ ____________
As altitude increases the barometric pressure decreases
Barometric pressure defintion
The pressure exerted by the earth’s atmosphere
___ decreases when altitude increases which has a severe impact on performance
PO2 decreases when altitude increases which has a severe impact on performance
Partial pressure at different diffusion gradients and altitudes (3)
Sea level pO2 = 159mmHg = Diffusion gradient of 119 to capillary blood
3600m above sea level pO2 = 105mmHg = Diffusion gradient of 65 to capillary blood; reduction of 45%
8800m above sea level pO2 = 105mmHg = Diffusion gradient of 3 to capillary blood
Consequences of High Altitude (4 things)
- Breathing frequency increases at rest and exercise in an attempt to maintain oxygen consumption
- Blood volume decreases; plasma volume decreases by 25% (first few hours) to increase the density of RBC’s in an attempt to maximise oxygen transportation
- SV decreases within the first few hours during sub-maximal exercise; which causes HR to increase to maintain and slightly raise CO
- Maximal CO, SV and HR decrease during maximum intensity exercise
Process of acute effects of high altitude (8 steps)
- Decreased pO2 in alveolar air
- Decreased diffusion gradient to the capillary blood
- Decreased haemoglobin and O2 association in the blood stream
- Decreased O2 transportation to the muscle tissue
- Decreased diffusion gradient to the muscle tissue
- Decreased O2 supply for aerobic energy production
- Increased breathing frequency, decreased blood volume and SV and increased HR
- Decreased VO2 max, aerobic capacity, intensity and duration of aerobic performance before fatigue
Acclimatisation definition
Process of gradual adaptations to a change in environment.
Altitude and how long it takes to acclimatise
1000-2000m
2000-3000m
3000m+
5000-5500m
1000-2000m = 3-5 days for low altitude performance
2000-3000m = 1-2 weeks for moderate altitude performance
3000m+ = 2+ weeks; athletes going above this should sleep no more than 300m each day and have regular rest days to prevent altitude sickness
5000-5500m = 4+ weeks for extreme altitude. For example a climber will spend 4 weeks at base camp before making an attempt to reach the summit of Everest.
Benefits of altitude training (4)
- Release of erythropoietin increases within three hours of altitude; peaking 24-48hrs later. This increases RBC production.
- Breathing rate and ventilation stabilise, BUT remain elevated at rest and during exercise compared with sea level
- SV and CO reduce as O2 extraction becomes more efficient. After 10 days CO is lower at sub-maximal intensity when compared with sea level. HR remains elevated
- Reduced incidence of altitude sickness, headaches, breathlessness, poor sleep and lack of appetite
Thermoreceptors definition
Sensory receptors which sense a change in temperature and relay the information to the brain
Describe the effects of high altitude exposure on performance in aerobic and anaerobic activities 5 marks
Three marks from
1 Decreased / lower (atmospheric)pressure / ppO2 at altitude or air thinner
2 Increased breathing frequency
3 Decreased blood / plasma volume
4 Decreased stroke volume
5 Decreased maximal cardiac output / max heart rate
6 Reduced pressure / diffusion gradient or reduced O2 uptake by muscles orreduced VO2 max / aerobic capacity orreduced oxygen transport / muscle delivery
Two marks for:
7 Lower performance in aerobic activities or decreased aerobic energyproduction or decreased intensity /duration before fatigue/ OBLA
8 Improved performance in anaerobic /explosive / throwing / jumping activities
Define what is meant by ‘acclimatisation to high altitude’. State one sporting activity in which performers wouldbenefit from it. 2 marks
- Adaptation/ get used to a change of environment/ lower O2 levels
- Marathon/ 5000m/ 10,000m runner/triathlete/ endurance cyclist/ fieldgames e.g. football/ endurance athlete
