Thermoregulation and altitude Flashcards
What is normal body temperature and shell temperature?
C - 36.5-37.5
S - 32-35
Physiological mechanisms to increase core temperature
- Release of epi
- Sweat glands
- Vasoconstrict/dilate vessels
- skeletal muscle contraction
How much energy is lost as heat during exercise?
75%
Why is a hot and humid environment considered the toughest environment to compete in?
High water content
Low temperature gradient
What happens when performing in heat and sweating?
Sweat reduces plasma volume
Decreasing SV and increasing HR
3 ways to mitigate heat stress prior, before and during performance in heat
- Heat acclimation
- Cooling aids
- Hydration
Name 5 physiological responses to performing in extreme cold environments
- Higher sub-max VO2max
- Reduced blood flow
- Lower lipid metabolism
- increased lactate concentration
- Decreased exercise capacity
What performance benefits and negatives have been seen in competitions at altitude?
Increased performance in high intensity
Decreased performance in endurance
What is the misconception with altitude?
People believe that % oxygen decreases, but in fact it is pressure
Short term responses to altitude exposure
- Immediate oxygen delivery
- Hyperventilation
- Alkalosis
- Increased HR and Q
What happens to sub-max exercise during altitude exposure?
Requires a higher VO2max for the same work completed at sea level
What happens during maximal exercise at altitude?
Decreased HR and lactate production
What happens at altitude in terms of hematocrit?
Release of polycythaemia stimulates EPO production and therefore RBC - increasing oxygen carrying capacity
Name 3 cellular adaptations with altitude
- Capillarisation
- Increased lactate oxidation
- Increased myoglobin
- Increased aerobic enzymes
