A2. Environmental factors and physical performance

Question 1

Conduction

Answer 1

The heat (moving energy) that has traveled from the core is transferred from the blood, to the body tissue and skin

Question 2

Radiation

Answer 2

The transfer of energy waves that are sent out from one object and absorbed by another.

Question 3

Convection

Answer 3

Heat is moved from one place to another through the movement of air (or water)

–> Warm particles rise up and cool particles rise down (fill the rest)

Question 4

evaporation

Answer 4

Evaporation is the conversion of sweat to water vapor (Liquid to Gas). As this process happens, heat is transferred from the body to the environment

Question 5

The cycle between ATP and ADP

Answer 5

When ATP is combined with water, it loses its phosphate.

This causes large amounts of energy to be released and ATP becomes ADP.

ATP can be remade in the opposite way, by adding a phosphate molecule back to the ADP. Energy is required for this as well.

–> Basically, repeating the cycle with adding phosphate and removing phosphate from ADP and ATP.

Question 6

The relationship between cellular metabolism and the production of heat in the human body.

Answer 6

The energy released when glucose reacts with oxygen is used in order to produce ATP. However, only a fraction of the released energy goes into the high-energy bonds of ATP. Some energy is lost as heat.

We then break down that ATP and use the energy to fuel muscle contraction. However, this is very inefficient since we use only about 20% of the energy for muscular contraction.

Question 7

The normal core body temperature at rest

Answer 7

The normal physiological range for core body temperature is approximate 36°C to 38°C

Question 8

The relation between body heat loss with respect to surfaces exposed to the low and high humidity environment.

Answer 8

• As humidity increases, no more water can evaporate. In hot conditions, sweat evaporates slower (causing the body to overheat).
• In low humidity, sweat evaporates quickly which may cause dehydration.

Question 9

Explain the relation between body heat loss with respect to the wind.

Answer 9

Wind causes body to perceive decreased temperature leading to hypothermia.

Less wind, less convection, and vice versa.

(Convection involves moving heat from one place to another by the motion of air movement)

Question 10

The relation between body heat loss with respect to humidity.

Answer 10

Evaporation, including sweating, becomes less efficient when humidity is high.

Question 11

Describe how the formation of sweat in order to maintain body temperature during exercise works.

Answer 11

1. Plasma is the source of sweat formation
2. Sweat is formed in the secretory parts of the sweat gland
3. Amount of sweat formed depends on the individual/ exercise intensity/ hydration status.

Question 12

Physiological responses that occur during prolonged exercise in the heat.

Answer 12

The reduced muscle blood flow in high temperatures results in increased glycogen breakdown in the muscle and higher levels of muscle and blood lactate in comparison to the same exercise performed in a cooler environment.

Question 13

Health risks associated with exercising in the heat.

Answer 13

Heat-related disorders include heat cramps, heat exhaustion and heat stroke.
Because of their relatively large body surface area and immature sweat response, infants, children and young adolescents are more susceptible to complications associated with exercise performed in the heat and the cold.

Question 14

Define what heat cramp is and steps that should be taken to prevent it.

Answer 14

It’s a type of heat illness, are muscle spasms that result from loss of large amount of salt and water through exercise.

• Stop exercise; rehydrate
• Massage/Light stretching

Question 15

Define what heat syncope is and steps that should be taken to prevent it.

Answer 15

In other word called fainting, it’s an illness when that results from Intense prolonged exercise in the heat

• Acclimatize
• Rehydrate
• Reduce exertion on hot days
• Avoid standing still in the heat

Question 16

Define heat exhaustion and outline steps that should be taken to prevent it.

Answer 16

Heat exhaustion is a condition whose symptoms may include heavy sweating and a rapid pulse, a result of your body overheating.

• Remove subject to shaded area/air conditioned area
• Hydrate before and during exercise
• Acclimatize

Question 17

Define heat stroke and outline steps that should be taken to prevent it.

Answer 17

Heat stroke is a type of severe heat illness that results in a body temperature greater than 40.0 °C (104.0 °F) and confusion.

• Immediate whole body cooling
• Acclimatize
• Adapt to climatic constraints

Question 18

How an athlete should acclimatize to heat stress.

Answer 18

• Performing training sessions in similar environmental conditions (heat and humidity) for 5 to 10 days results in almost total heat acclimatization.
• The intensity of training should be reduced to avoid heat-related problems in these conditions.

Question 19

What is the ethical consideration for an athlete when they acclimatize to heat stress?

Answer 19

There’s an ethical implication that poorer nations will be unable to afford such support mechanisms and so their athletes are disadvantaged in comparison to athletes from wealthier nations.

Question 20

Physiological and metabolic adaptations that occur with heat acclimatization in long term adaptation

Answer 20

• Increased plasma volume
• Increased sweat response
• Reduced rate of muscle glycogen utilization

Question 21

Explain the principal means by which the body maintains core temperature in cold environments.

Answer 21

• shivering
  
  • (repeated muscular contractions
  • uses up extra oxygen and glucose/glycogen stores.
• non-shivering thermogenesis)
  
  • (The cold stimulates adrenaline which acts on BAT to break down Trigycerides into FFA and Glycerol.

FFA undergo oxidation in the mitchondria releasing heat)

• peripheral vasoconstriction.
  
  • (Constriction of the blood vessels close to the skin and skeletal muscles, meaning more blood remains near the core.
  • keeps the core temperature elevated and decreases the heat transferred to the environment.)

Question 22

why is the body surface area-to-body mass ratio is important for heat preservation

Answer 22

The ratio of body surface area to body mass affects the rate of heat loss.

A larger surface area to body mass ratio = Increased heat loss

A lower surface area to body mass ratio = decreased heat loss.

Higher SA allows more sweating to cool the skin with evaporation and convection

Question 23

What causes wind- chill, in relation to body heat loss

Answer 23

A chill factor created by the increase in the rate of heat loss via convection and conduction caused by wind.

Question 24

Why swimming in cold water represents a particular challenge to the body’s ability to thermoregulate

Answer 24

During cold-water immersion, humans generally lose body heat and become hypothermic at a rate proportional to the thermal gradient and the duration of exposure.
During swimming, the effect of cold water on body heat loss is increased because of greater convective heat loss. However, at high swimming speeds, the metabolic rate of the swimmer may compensate for the increased heat loss.

Question 25

Physiological responses to exercise in the cold

Answer 25

• Decrease in muscle contractility (ability to contract)
• Decrease in the power and velocity of muscle contraction
• Prolonged exercise in the cold depletes glycogen stores and can lead to an inability to maintain blood glucose.

Question 26

Health risks of exercising in the cold, including cold water

Answer 26

• Hypothermia
  
  • Body’s core temperature falls below 35 which is required for body function
• Frostbite
  
  • Constant freezing of the cells and can lead to cell death.

Question 27

Precautions that should be taken when exercising in the cold.

Answer 27

• The main precaution that should be taken when exercising in the cold, is clothing.
• Decrease amount of skin in contact with the environment in high wind-chill.
  
  • Decrease the amount of convective heat loss
• Provide insulation for feet, hands, ears
  
  • The hands/fingers, feet/toes and ears are the parts of the body most prone to frostbite.
• Preserve a warm core temp
  
  • Warm core temp means warm extremities
• Increased carbohydrate intake
  
  • Account for increased glucose/glycogen use during exercise in the cold

Question 28

Why is there increased hydration while exercising in the cold?

Answer 28

Exercise in cold results in increased breathing rates, increased heat production and therefore increased potential for dehydration

Question 29

Why is the clothing requirement is dependent on the intensity of exercise and environment

Answer 29

Too much clothing can lead to heat stress from excess heat production and decreased ability to remove heat.