Environmnetal effects Flashcards
What is altitude?
Elevation above sea level
What happens the partial pressure of oxygen as altitude increases?
The partial pressure of oxygen decreases
As altitude increases what happens to the rate of oxygen diffusion and what does this mean?
The rate of oxygen diffusion decreases. This reduces haemoglobin transportation and results in poor transport of oxygen
Less oxygen transport to muscles.
Less oxygen diffuses into blood
What happens at altitude to decrease aerobic capacity and VO2 max?
Decrease blood volume
Decrease SR but increase HR
Decrease in max CO, SV and HR
What is the effect on sub-maximal exercise pre acclimatisation?
Aerobic performance deteriorates
Reversibility occurs
Decrease VO2 max
Early fatigue
Early lactate threshold and OBLA
How longs does it take do acclimatise to:
1. 1000-2000m
2. 2000-3000m
3. 3000-5000m
4. 5000m+
- 3-5 days
- 1-2 weeks
- 2-4 weeks
- 4+ weeks
What are the cardiovascular adaptations after 4 weeks of altitude training?
Increased capillary density
Increased release of EPO
Increased RBC count
Decrease SV and Q
Increases oxygen carrying capacity
What are the respiratory adaptations after 4 weeks of altitude training?
Increased SA of alveoli
Increased capacity for diffusion
Increased strength of respiratory muscles
What is the effect on sub-maximal exercise post acclimatisation?
Aerobic performance improves
Increased VO2 max
Delayed fatigue
Delayed lactate threshold and OBLA
How long do benefits from altitude training last?
3 weeks after returning to sea level
What is hyperthermia?
An increase in core body temperature
In temperatures above 32c, how can breathing become difficult and what does this cause?
Breathing can become more difficult due to dehydration and the drying of airways.
This can cause:
- increased mucus production
- constriction of airways
- decreased volume of air for gaseous exchange
What is cardiovascular drift?
An upward drift in HR that is associated with a rise in core body temperature. A 1 degree rise can increase HR by 10bpm.
What are the effects of heat on the respiratory system?
Drying of airways making breathing difficult. This reduces the volume of air flow for gas exchange.
Increases breathing frequency.
Increases irritation of airways due to increased pollen.
What are the effects of heat in the cardiovascular system?
Decreased volume of blood plasma, which results in an increase in HR to maintain oxygen delivery to muscles. This leads to cardiovascular drift.
Blood pooling at the skin occurs which causes a decrease in VR and therefore SV. This means that less blood delivers oxygen to muscles. This means that HR increases to maintain Q and the delivery of oxygen to muscles, leading to cardiovascular drift.
