D2 - Responses of Body Systems to High Altitude

• Initial Responses of Body to High Altitude:

  • The body’s initial responses to being at high altitude are:
  • An increase in respiratory rate (hyperventilation)
  • An increase in heart rate (tachycardia)
  • Hypoxia, which is where the body has lower levels of oxygen then required
• Initial Responses of Body to High Altitude:

  • When a person arrives at high altitude, their respiratory rate and depth increase. 
  • The increased breathing rate has the effect of causing more carbon dioxide to be expired and more oxygen to be delivered to the alveoli.
  • The respiratory rate peaks after about one week of living at high altitude, and then slowly decreases over the next few months, although it tends to remain higher than its normal rate at sea level.
• Initial Responses of Body to High Altitude:

  • Heart rate increases because the body’s cells require a constant supply of oxygen. 
  • As there is less oxygen available in the blood, the heart beats more quickly to meet the cells’ demands. 
  • However, the heart rate will also start to decrease as more time is spent at high altitude.
• Reduced VO2 Max:

  • Due to the fact there is a lower partial pressure of oxygen in the air, a person’s VO2 will be reduced when they arrive at altitude.
  • VO2 max is a measure of the body’s ability to uptake and use oxygen.
  • However, if there is less oxygen available in the air then the ability to uptake oxygen is reduced which results in a reduced VO2 max.
• Altitude Sickness:

  • A person may suffer from altitude sickness initially, but a person’s fitness levels do not appear to have any effect on whether they will suffer from this condition or not.
  • Altitude sickness includes the following symptoms:
  • Headache
  • Nausea
  • Dizziness
  • Exhaustion