wk2 personal factors governing heat tolerance

Question 1

how does body type make a difference in heat

Answer 1

larger body surface area provides more area for sweat production
dry heat loss is also enhanced with a larger body surface

influences heat production and thermoregulatory responses

Question 2

how does body surface area-to-mass ratio affect heat storage

Answer 2

higher ratio means less heat storage, due to larger area for dry and evaporative heat loss

Question 3

what is the similarity between total body water and blood volume

Answer 3

both experience expansion with endurance exercise - independent of body size or sex

Question 4

what are heat shock proteins induced by

Answer 4

heat + exercise
hypoxia
infections and inflammation

Question 5

how do HSP play a sig. role in heat adaption

Answer 5

proposed mechanism via maintenance of gut tight
epithelial junctions
reducing risk of endotoxemia (gut leakage)

Question 6

how does aerobic fitness improve heat tolerance

Answer 6

total body weight and blood volume, helps offset quicker dehydration
Increased sweat and skin blood flow
Small benefit from increased work rate
Lower core temp at rest and submax
Higher absolute core temp tolerated
More HSP production
Glycogen sparing

Question 7

what are the two predictors of exercise tolerance

Answer 7

maximal aerobic power
training status

Question 8

how can sex differences affect heat stress

Answer 8

women had lower vo2 max, body surface area and body mass index

however women had a higher body surface area-to-mass ratio and body fat% so more likely to be heat tolerant

Question 9

sex differences in exertional heat stroke

Answer 9

females had lower risk of EHS but may be modifiable by age

Question 10

similarity in both sex’s dealing with heat stress

Answer 10

sweat production
increase in skin blood flow
onset thresholds
thermosensitivity
sweat gland activation
sweat gland output

Question 11

how do men cope better with heat stress

Answer 11

ONLY IN VERY HIGH AMBIENT TEMPS
sweat production
sudomotor thermosensitivty
sweat gland output

Question 12

what is the process of dealing with heat production and high temps

Answer 12

higher temp -> thermoreceptors -> CNS -> sudomotor activity + vasomotor activity

Question 13

what are the differences between sex’s in temporal adaption heat acclimation

Answer 13

females require longer to achieve thermoregulatory and cardiovascular heat adaptions

Question 14

what affect does ageing have on heat stress

Answer 14

reduced sweat gland output
reduced skin blood flow
smaller increase in cardiac output
less redistribution of blood flow from renal and splanchnic circulations

Question 15

how does spinal cord injury affect heat stress

Answer 15

causes a loss or reduction in sweating capacity impaired vasomotor control

results in an imbalance between heat gain and heat loss occuring more readily with exercise in the heat

Question 16

what factors affect exercise in hot conditions

Answer 16

body size
aerobic fitness
sex
age
spinal cord injury

Question 17

relative vs absolute vo2 max

Answer 17

relative - relative to individual body mass

Question 18

why do smaller athletes have a worse time dealing with heat

Answer 18

less capacity means they got hotter faster

Question 19

what is sweat production linear to

Answer 19

the body surface area

Question 20

link between fitness and tolerance

Answer 20

fitter = better tolerance

Question 21

how does fitness affect thermoeffector response

Answer 21

causes ‘shift to left’ means start sweating sooner and causes steeper rate of increase and higher maximal value

Question 22

link between HSP and tolerance

Answer 22

linear relationship, more = higher tolerance

Question 23

what happens in the gut within high heat

Answer 23

cell walls become further apart and proteins slip through the gut causing stomach aches

Question 24

how can training status change tolerance

Answer 24

acute effects on - kindeys Na retention and albumin production alongside HSP production

Question 25

what can drive sex differences in heat tolerance

Answer 25

anthropometrics and cardiovascular fitness impacts the most

Question 26

different characteristics that can affect sex differences

Answer 26

men have higher:
vo2 max
bm
men have lower:
BSA : MASS
hormone fluctuation

Question 27

what happens to women during the menstrual cycle

Answer 27

causes a higher core body temperature, may allow them to reach higher temps and increase heat tolerance (only a maybe,, start higher end higher)

Question 28

differences between sex’s in acclimation

Answer 28

females may take longer to see thermoregulatory and cardiovascular heat adaptions, takes around 9days rather than 4/5

over a longer period (3wks) changes adapt similarly

Question 29

sex differences in thermoeffector adaptions

Answer 29

males increased forearm blood flow

females increased forearm sweat gland activation

Question 30

how does hormonal contraception

Answer 30

dims variation that can occur during the menstrual cycle

Question 31

how does spinal cord affect thermoregulation

Answer 31

damage central drive affects/impairs:
sweating
skin blood flow
muscular heat production

Question 32

other factors affecting performance in heat

Answer 32

medication
illness
fatigue and sleep deprivation
initial thermal stress