Lecture 7 - Extreme environments Flashcards
What is the conc of O2 and N2 particles at high and low sea level
High: 2 oxygen &
8 Nitrogen
Low: 7O2 and 28N2
What are the effects of altitude on short term and long term anaerobic and aerobic performance
Short term anaerobic: lower PO2 at altitude should have no effect of performance, lower air resistance may improve performance & recovery may be impaired
long term aerobic: Lower PO2 results in poorer aerobic performance dependent on oxygen delivery to the muscle.
What are the effects on maximal aerobic power and altitude
Decreased VO2 max at higher altitude due to lower oxygen extraction and decreased arterial PO2, also due to decrease HR and therefore Q
What is the effect of acclimatization to altitude
ST: Increased delivery
LT: Increased efficiency
what are the effects of Hypoxia
Increase RR HR constriction of lung vessels and dilate peripheral blood vessels
effect of altitude on sub-maximal exercise
Increased HR - lower O2 blood content
Increased RR - reduction in number of 02 molecules
Acclimatization to higher altitudes does 2 things: what are they.
Increased more RBCs due to increased EPO
Greater O2 saturation due to an increase in blood flow to the lungs.
what are the 8 factors affecting heat injury
Acclimatization fitness clothing environmental humidity metabolic rate environmental temperature wind hydration
What is the cold shock response
Rapid fall in skin temp, uncontrolled CR responses, difficult to hold breathe
easy to ingest large water volumes
exercise economy and efficiency in the cold
maintain intensity elicits a higher VO2
30% VO2 max = glycogen degradation and CHO oxidation rates are greater
What are the performance impairments of the cold
Shivering increased motor unit recruitment decreased muscle tendon elasticity increased stride frequency and decreased stride length lower mechanical efficiency
describe the temperature drops leading to hypothermia
hypothermia = 35 2 degree drop = maximal shivering 3 = reduced cerebral flow and cognitive function 4 ataxia and apathy 6 unconciousness death
factors affecting hypothermia
Heat production
environmental factors
descriptive characteristics
insulating factors
Thermoregulation equation
Heat storage = Metabolism +- radiation +- conduction +- convection - evaporation
what are the 5 avenues of heat loss
Metabolism / radiation / conduction / convection / evaporation
