Environmental effects of body systems Flashcards
1.1d content
Define the term barometric pressure
The pressure exerted by the earths atmosphere at any given point
What happens to barometric pressure when altitude increases
It decreases
As altitude increases, barometric pressure decreases
What causes athletes’ performance to decrease
The lower partial pressure of oxygen (pO2) decreases. The greater the altitude the greater the negative impact on the diffusion gradient causing diffusion to happen at a decreased rate
What 3 main effects does altitude have on the body?
- Blood volume decreases
- Stroke volume decreases which increases HR
- Maximal cardiac output, stroke volume and heart rate decrease during maximum intensity exercise
Define the term acclimatisation
A process of gradual adaption to a change in environment (eg lower oxygen at altitude)
How long does acclimatisation take for low altitude (1000-2000m)
3-5 days
How long does acclimatisation take for moderate altitude (2000-3000m)
1-2 weeks
How long does acclimatisation take for high altitude (3000m+)
2 weeks +
How long does acclimatisation take for extreme altitude (5000-5500m)
4 weeks +
What are the 4 main benefits of acclimatisation?
- Increase in red blood cell production due to an increase release of erythropoietin
- Breathing rate and ventilation stabilise although remain elevated at res compared to sea levels
- SV and CO reduce as oxygen extraction becomes more efficient
- Reduce incidents of altitude sickness, headaches, breathlessness, poor sleep and lack of appetite
Define the process thermoregulation
The process of maintaining internal core temperature
What do thermoreceptors detect and what do they do in response to change
- Temperature change deep in the core of the body
- If core temperature rises, metabolic heat is transported by the circulating blood to the surface of the body and release mostly by convection and evaporation (sweat)
What are the main side-effect of exercising in the heat
Dehydration due to sweating
What 3 things is hyperthermia (significantly raised core body temperature) caused by?
- High and prolonged exercise intensities
- High air temperature
- High relative humidity
Define the term cardiovascular drift
During prolonged exercise in the heat, a rise in core body temperature can cause cardiovascular drift: an upward drift in heart rate associated with a rise in body temperature
Highlight the 2 effects of heat and humidity on the cardiovascular system
- Dilation of arterioles and capillaries to the skin
- increased blood flow and blood pooling in the limbs
- Decreased blood volume, venous return, SV, CO and BP
- increased HR too compensate
- increased strain on the cardiovascular system
- reduced O2 transport to the working muscles
Highlight the 3 effects of heat and humidity on the respiratory system
- Dehydration and drying of the airways in temps about 32 makes breathing difficult
- increased mucus production
- constriction of the airways
- decrease volume of air for gaseous exchange
- Increased breathing frequency to maintain oxygen consumption
- increase oxygen cost of exercise
- High levels of sunlight increase the effects of pollutants in the air
- increased irritation of airways, leading to coughing, wheezing or asthma symptoms
State 2 strategies to maximise performance in heat and humidity pre comp
- 7-14 days of acclimatisation in the same conditions to increase the body’s tolerance in heat
- Using cooling aids such as ice vests to reduce core temp and delay the effects of dehydration
State 3 strategies to maximise performance in heat and humidity during comp
- Pacing strategies to reduce the feelings of exertion at low-exercise intensities
- Wear suitable clothing to maximise heat loss
- Rehydrating as often and as much as possible with a hypotonic or isotonic solution
State 2 strategies to maximise performance in heat and humidity post comp
- Use cooling aids
- Rehydrate using isotonic solutions to replace lost fluids, glucose and electrolytes
