Heat and altitude Flashcards
What is cardiovascular drift (4)
Cardiovascular drift is the side effects of exercise in a hot climate
Cardiovascular drift leads to an increased heart rate at given intensity
Reduced plasma volume / (due to) water loss during exercise
(which means) reduced stroke volume to maintain cardiac output HR has to increase
Effects of high altitude on aerobic and anaerobic activities (2)
Lower performance in aerobic activities or decreased aerobic energy production or decreased intensity / duration before fatigue / OBLA
Improved performance in anaerobic activities e.g. Throwing
Define what is meant by ‘acclimatisation to high altitude’.
Adaptation/ get used to a change of environment/ lower O2 levels
Identify effects which exercise in the heat can have on the cardiovascular system. (5)
Increased heart rate/ cardiovascular drift
Vasodilation of arteries/arterioles to skin or increased blood flow to skin
Decreased stroke volume
Decreased venous return
Reduced oxygen/oxygenated blood to muscles
short-term effects of performing at high altitude on the cardiovascular system.
[4]
Increase in heart rate
Decrease in stroke volume
Decrease in blood / plasma volume
Decrease in O2 transport to muscle
short-term effects of performing at high altitude on the respiratory systems. [4]
Increase in tidal volume / depth
Increase in breathing rate / frequency
Decrease in ppO2 in inspired air
Decrease in oxygen diffusion gradient from alveoli to (capillary) blood
How long before a match should a team arrive at this altitude in order to acclimatise?
At least 2 weeks
Describe the physiological processes of acclimatisation to altitude.(4)
Decrease in stroke volume compared to arrival
Increased red blood cell volume
Breathing rate stabilizes
Increased capilirisation
Additional Positives – post acclimitisation
- Increased number and surface area of alveoli
- Increased capillary density at alveoli and the muscles
- Increased capacity for gaseous exchange
- Increased haemoglobin, red blood cells
- Increased oxygen carrying capacity – increased oxygen to muscles
- Increased strength of respiratory muscles
- Increased lung volumes and capacity and depth of breathing/ tidal volume
- Aerobic capacity increased
- VO2 max increased
- Increased mitochondria (produce energy)
- Increased buffering capacity – the ability to resist changes in pH
Immediate negatives of altitude training
- Decrease in atmospheric pressure/air thinner
- Breathing frequency to increase
- Hyperventilation - Decrease in pressure of 02
- Decrease in efficiency of external respiration
- Decrease in p02 in the alveoli
- Shallower or reduced o2 diffusion gradient (alveoli and blood)
- Less o2 diffuses into blood/capillaries
- Decreases gaseous exchange
- Less o2 combines or associates with haemoglobin / haemoglobin is less saturated
- Decrease in p02 in the blood - Less o2 is transported in the blood/ less oxygen is transported to the working muscles
- Decrease in efficiency in internal respiration
- Shallower or reduced o2 diffusion gradient between the blood and muscle
- Decrease is o2 dissociation
- Less 02 diffuses into the muscle cell/ decreased gaseous exchange between the blood and the muscle - Increase in chemoreceptor stimulation
- Chemoreceptors detect lower 02 levels or lower p02
- Information sent to RCC in medulla oblongata
- Inspiratory centre and expiratory centre stimulated
- This leads to increased depth and rate of breathing - Can lead to hypoxia
- Increased risk of altitude sickness/ dizziness/ vomiting - Air is dryer/ colder
- Increased risk of dehydration
Effects of exercise in heat on respiratory systems
Dehydration and drying of airways
Increased mucus production
Constriction of airways
Decreased volume of air for gaseous exchange
Increased breathing frequency
