Option A.5 Flashcards
State the height ranges for different categories of altitude
Near sea level: 0–500 m
- Low altitude: 500–2,000 m
- Moderate altitude: 2,000–3,000 m
- High altitude: 3,000–5,500 m
- Extreme altitude: above 5,500 m
Define hypoxia
A condition in which the oxygen supply to cells is insufficient.
Outline the physiological effects of altitude
Respiratory responses (such as hyperventilation)
- Cardiovascular responses (such as elevated submaximal heart rate)
- Metabolic responses (e.g. production of energy and lactic acid via glycolysis may be limited).
Respiratory responses altitude
Pulmonary ventilation at rest and during exercise has to increase at altitude to make up for the lack of 02 in the air(PP02).
Increased ventilation moves more 02 into the lungs but also more CO2 out of the lungs. This leads to more CO2 moving out of the bodies tissues and results in respiratory alkalosis (blood pH to increase).
Cardiovascular responses
Cardiac Output
Another compensation for the lower oxygen availability is an increase in the oxygen delivery or increased cardiac output. This increased cardiac output occurs at rest and during submaximal exercise. This is accomplished by an increased heart rate, but a decreased stroke volume (decreased plasma volume).
Metabolic responses altitude
production of energy and lactic acid via glycolysis may be limited
Outline the effects of altitude on fluid balance
Ambient air at elevated altitude is cool but humidity is low, enhancing fluid loss and leading to dehydration.
Fluid loss is exacerbated as a result of physical activity at altitude.
Altitude-induced diuresis (increased urine production) also occurs.
Outline altitude training.
This is training for endurance athletes at altitudes above 2,000m for several weeks or months in order to gain a competitive advantage in low altitude competitions
Training at moderate or high altitude, where the oxygen partial pressure is low, can trigger the release of the hormone erythropoietin (EPO), which stimulates increased red blood cell production.
What hormone is released at high altitude
Training at moderate or high altitude, where the oxygen partial pressure is low, can trigger the release of the hormone erythropoietin (EPO), which stimulates increased red blood cell production.
Live High, Train High
+ve Maximum exposure to altitude
+ve Stimulus on the body is constant
-ve Cannot train at as high an intensity as at sea level
-ve Takes a long time of acclimatize = no training
Research - Little support of training effects
- Possible improvement in power output but training intensities are compromised.
Live Low, Train High
+ve No altitude effects in daily life (no headache, no dehydration, no dizziness).
+ve lower intensity training but altitude sickness a problem
-ve Cannot train at as high an intensity as at sea level so some athletes report that they have lost fitness.
Research - Some findings suggest this can work, but nothing concrete
Live High, Train Low
+ve High time spent at altitude
+ve Training at sea level can be very intense
-ve Have to live at altitude for at least 3 weeks.
Research - Improvements in sea level performance have been shown in events lasting between 8 and 20 minutes.
- Most effective compared to others (esp. Aerobic adaptations)
Define the impact of altitude on sports performance.
Sporting Performances Enhanced by altitude:
At altitude, air is less dense, which means when a body moves through air it has less resistance and drag acting on it.
Therefore, in sports where things are thrown/shot, or people more through the air at high speed, performances would be enhanced.
Examples are baseball hitting, javelin
throwing, 100m, ski jumping and speed
skating.
Sporting Performances Impaired by altitude:
At altitude, air is less dense, which means there are less oxygen particles for any given volume of air.
Therefore, it is harder to get oxygen into the lungs and alveoli, so sports which require a high proportion of VO2 Max tend to be impaired at altitude.
Examples are marathon running,
long distance cycling, cross country skiing
Explain the adaptations resulting from altitude hypoxia.
Blood Adaptations:
-Increased number of red blood cells
Muscle Adaptations:
-Reduced lean body mass
-increased capillary density at the muscles
Cardiorespiratory Adaptations:
-Deeper and faster breathing at rest and in exercise.
-Increased number of alveoli.
-Increased capillary density at the lungs.
Distinguish between AMS, HAPE and HACE
AMS Acute Mountain Sickness
HAPE High Altitude Pulmonary Edema
HACE High Altitude Cerebral Edema
