Environmental effects of body systems

Question 1

Define the term barometric pressure

Answer 1

The pressure exerted by the earths atmosphere at any given point

Question 2

What happens to barometric pressure when altitude increases

Answer 2

It decreases

As altitude increases, barometric pressure decreases

Question 3

What causes athletes’ performance to decrease

Answer 3

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

Question 4

What 3 main effects does altitude have on the body?

Answer 4

1. Blood volume decreases
2. Stroke volume decreases which increases HR
3. Maximal cardiac output, stroke volume and heart rate decrease during maximum intensity exercise

Question 5

Define the term acclimatisation

Answer 5

A process of gradual adaption to a change in environment (eg lower oxygen at altitude)

Question 6

How long does acclimatisation take for low altitude (1000-2000m)

Answer 6

3-5 days

Question 7

How long does acclimatisation take for moderate altitude (2000-3000m)

Answer 7

1-2 weeks

Question 8

How long does acclimatisation take for high altitude (3000m+)

Answer 8

2 weeks +

Question 9

How long does acclimatisation take for extreme altitude (5000-5500m)

Answer 9

4 weeks +

Question 10

What are the 4 main benefits of acclimatisation?

Answer 10

1. Increase in red blood cell production due to an increase release of erythropoietin
2. Breathing rate and ventilation stabilise although remain elevated at res compared to sea levels
3. SV and CO reduce as oxygen extraction becomes more efficient
4. Reduce incidents of altitude sickness, headaches, breathlessness, poor sleep and lack of appetite

Question 11

Define the process thermoregulation

Answer 11

The process of maintaining internal core temperature

Question 12

What do thermoreceptors detect and what do they do in response to change

Answer 12

1. Temperature change deep in the core of the body
2. 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)

Question 13

What are the main side-effect of exercising in the heat

Answer 13

Dehydration due to sweating

Question 14

What 3 things is hyperthermia (significantly raised core body temperature) caused by?

Answer 14

1. High and prolonged exercise intensities
2. High air temperature
3. High relative humidity

Question 15

Define the term cardiovascular drift

Answer 15

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

Question 16

Highlight the 2 effects of heat and humidity on the cardiovascular system

Answer 16

1. Dilation of arterioles and capillaries to the skin

• increased blood flow and blood pooling in the limbs

2. 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

Question 17

Highlight the 3 effects of heat and humidity on the respiratory system

Answer 17

1. 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

2. Increased breathing frequency to maintain oxygen consumption

• increase oxygen cost of exercise

3. High levels of sunlight increase the effects of pollutants in the air

• increased irritation of airways, leading to coughing, wheezing or asthma symptoms

Question 18

State 2 strategies to maximise performance in heat and humidity pre comp

Answer 18

1. 7-14 days of acclimatisation in the same conditions to increase the body’s tolerance in heat
2. Using cooling aids such as ice vests to reduce core temp and delay the effects of dehydration

Question 19

State 3 strategies to maximise performance in heat and humidity during comp

Answer 19

1. Pacing strategies to reduce the feelings of exertion at low-exercise intensities
2. Wear suitable clothing to maximise heat loss
3. Rehydrating as often and as much as possible with a hypotonic or isotonic solution

Question 20

State 2 strategies to maximise performance in heat and humidity post comp

Answer 20

1. Use cooling aids
2. Rehydrate using isotonic solutions to replace lost fluids, glucose and electrolytes