Lecture 20 Flashcards
Exercise at Altitude
what are the stressors of a high altitude environment
- Decrease PO2 (due to decerease PB)
- Decrease Temperature (1°C/150 m)
- Decrease Humidity
- Decrease liquid Water
- Increase Wind
- Increase UV Radiation
what are the physiological effects of a high altitude environment
- Increased Ventilation
- decreased fluid & energy in
- increased Glycolysis & energy use
- decreased gut absorption
- increased catabolism
what is physiological stress at altitude mainly due to
limited PO2 diffusion gradient
how is aerobic power affected with increased altitude
non linearly
- more effect as you go to higher altitudes
why are you able to jump and throw further in higher altitude conditions
reduced air resistance
what is the degree of response to altitude generally proportional to
the level of altitude
what are the acute responses to altitude
increased heart rate and ventilation at rest and submaximal exercise
then begin to increase haematocrit as fluid is lost
what do adaptive responses to altitude also include
peripheral changes
what is variability in acute and adaptive responses to altitude not related to and what does this mean the variability is related to
not related to sex, fitness, age etc
large inter-individual variability
why is the first response of acute cardiorespiratory responses to altitude hyperventilation
due to low partial pressure of inspired oxygen
what does hyperventilation in response to altitude cause
to become more alkaline
what are the long term effects of high altitude on muscle
- increased mitochondrial density
- capillaries may become more dense
- increased aerobic enzymes
when is acute mountain sickness common
during the first several hours to days >3000m
what is acute mountain sickness directly related to
speed of ascent and final altitude
does acute mountain sickness have anything to do with genetics
partly related (cardiorespiratory control)
what gender is acute mountain sickness less common in
less common in females
what are the symptoms of acute mountain sickness (4)
- severe headache
- dizziness and dim vision
- nausea, vomiting and constipation
- insomnia and weakness
how can you prevent acute mountain sickness
- gradual ascent (1 day rest @2500m, ascend ~600m/day after that)
- high CHO diet and well hydrated
- drugs
how common is high altitude cerebral oedema and what can happen is untreated
not common (1%) but readily fatal if untreated
what are the symptoms of high altitude cerebral oedema
more severe version of acute mountain sickness
- also loss of motor control, poor reflexes and confusion
what is the treatment for acute mountain sickness
- time
- drugs
- oxygen or descent if severe
how common is high altitude pulmonary oedema
not common (2% males)
symptoms of high altitude pulmonary oedema (5)
fatigue
low saturation of O2
chest pain and tightness
dry cough
very bad symptoms
what are causes of high altitude pulmonary oedema
- pulmonary hypertension
- reactive oxygen species in the lung
what is the treatment of high altitude pulmonary oedema
assisted / stretchered descent
what improvement is seen in sea level performance from altitude training
slight improvement, 1-4% on average
what method of altitude training seems to be most effective
live high, train high + low
at a given intensity during submaximal exercise in high altitude conditions will heart rate be higher or lower than at sea level
heart rate will be higher at high altitude
