A.2 - Environmental Factors and Physical Performance Flashcards
Conduction
Radiation
transfer of energy waves that are sent out from one object and absorbed by another.
Convection
Heat moved from one place to another through the movement of air/water
Evaporation
- The conversion of sweat to water vapor (liquid → gas)
- Heat from body → environment
The cycle between ATP and ADP
ATP + water → loses its phosphate → large amounts of energy released → ADP
To reverse:
ADP + P = ATP (requires energy asw)
The relationship between cellular metabolism and the production of head in the human body
Normal Core Body Temperature at Rest
36ºC - 38ºC
The relation between body heat loss with respect to surfaces exposed to the low and high humidity environment
High humidity:
- In hot conditions → sweat evaporates slower → body overheat
Low humidity:
- Sweat evaporates quickly → dehydration
Explain the relation between body heat loss with respect to the wind
- Wind → cause body to pervice temperature decrease → hypothermia
- Wind ↓ = Convection ↓
The relation between body heat loss with respect to humidity
High humidity:
Evaporation, including sweating becomes less efficient
Describe how the formation of sweat in order to maintain body temperature during exercise works
- Plasma = source of sweat formation
- Sweat is formed in secretiry parts of sweat glands
- Amount of sweat formed depends on individual/exercise intensity/hydration status
Physiological responses that occer during prolonged exercise in the heat
- increased glycogen breakdown
- level of muscle and blood lactate ↑
Health risks associated with exercising in the heat
- Heat cramps
- Heat exhaustion
- Heat stroke
Define what heat cramp is and steps that should be taken to prevent it
- Muscle spasms that result from loss of large amount of salt and water
What to do to prevent it?
- Stop exercise; rehydrate
- Massage / Light stretching
Define what heat syncope is and steps that should be taken to prevent it
- Also known as fainting
- An illness that results from intense prolonged exercise in the heat
What to do to prevent it?
- Acclimatize
- Rehydrate
- Reduce exertion on hot days
- Avoid standing still in the heat
Define heat exhaution and outline steps that should be taken to prevent it.
Symptoms:
- Heavy sweating, rapid pulse → overheating
What to do to prevent it?
- Remove subject to shaded area / AC area
- Hydrate before / during exercise
- Acclimatize
Define heat stroke and outline the steps that should be taken to prevent it
- Type of severe heat illness that results from body temp > 40.0 ºC and confusion
What to do to prevent it?
- Immediate whole body cooling
- Acclimatize
- Adapt to climatic constraints
How an athlete should acclimatize to heat stress
- Perform training sessions in similar environment conditions for 5 - 10 days
- Intensity of training should be reduced to avoid heat-related problems
What is the ethical consideration for an athlete when the acclimatize to heat stress?
Poorer nations will not be able to afford support mechanisms → atheletes are disadvantaged
Physiological and metabolic adaptations that occur with heat acclimatization in long term adaption
- Increased plasma volume
- Increased sweat response
- Reduce rate of muscle glycogen utilization
Explain the principal means by which the body maintains core temperature in cold environments.
- Shivering
- Non - shivering thermogenesis
- Peripheral vasoconstriction
Shivering
- Repeated muscular contraction
- Uses up extra oxygen and glucose/glycogen store
Non-shivering thermogenesis
Cold triggers adrenaline → activates BAT → break down triglycerides → FFA & Glycerol
Peripheral vasoconstriction
- Blood vessels near skin and muscles constrict, keeping more blood in the core.
- Helps maintain core temperature and reduces heat loss.
Why is the body surface area-to-body mass ratio is important for heat preservation
- Larger surface area : body mass = heat loss ↑
- Lower surface area : body mass = heat loss ↓
- Higher SA = more sweating → cool skin with evaporation & convection
What causes wind- chill, in relation to body heat loss
Rate of heat loss ↑ via convection & conduction caused by wind
Why swimming in cold water represents a particular challenge to the body’s ability to thermoregulate
- In cold water, heat loss and risk of hypothermia depend on temperature difference and time exposed.
- Swimming increases heat loss due to convection.
- High swimming speeds can offset this with increased metabolic heat production.
Physiological responses to exercise in the cold
- Decrease in muscle contractility
- Decrease in the power and velocity of muscle contraction
- Depletes glycogen stores → an inability to maintain blood glucose.
Health risks of exercising in the cold, including cold water
Hypothermia:
- Body’s core temperature falls < 35ºC
which is required for body function
Frostbite:
- Constant freezing of the cells and can lead to cell death.
Precautions that should be taken when exercising in the cold.
Main precaution 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 bc they are most prone to frostbites
- Preserve a warm core temp = warm extremities
- Increased carbohydrate intake → Account for increased glucose/glycogen use during exercise in the cold
Why is there increased hydration while exercising in the cold?
Increased breathing rates & heat production → increased potential for dehydration
Why is the clothing requirement is dependent on the intensity of exercise and environment
Too much clothing can lead to:
- heat stress from excess heat production
- decreased ability to remove heat
