Environment

Question 1

Type of heat gain in the body? (Kenney et al. 2012)

Answer 1

Metabolic heat

Environment - conduction, convection, radiation

Question 2

Types of heat loss in the body? (Kenney et al. 2012)

Answer 2

Radiation
Condition
Convection
Evaporation

Question 3

Define conduction?

Answer 3

Heat transfer through a solid surface

Question 4

Define convection?

Answer 4

Heat transfer through an aqueous or gaseous substance

Question 5

Define radiation?

Answer 5

Heat is given off by our bodies that we absorb

Question 6

What affects heat loss?

Answer 6

Temperature

Humidity

Question 7

How is thermoregulation controlled?

Answer 7

Controlled through the sympathetic nervous system

Blood temperature sensed by the hypothalamus

Question 8

Thermoregulatory responses to the heat?

Answer 8

Vasodilation in the skin blood vessels redistributes blood flow and increases heat loss from the skin
Sweat glands become active, increasing heat loss through evaporation

Question 9

Physiological responses to exercise in the heat?

Answer 9

Skin arterioles vasodilate to increase skin blood flow
Increased Q
Decreased SV (sweat) -> increased HR (cardiac drift)
The heart cannot provide sufficient blood flow to the heart and skin
Decreaed performance
Increased sweating -> decreased blood volume -> decreased Q

Question 10

Considerations for a race in the heat?

Answer 10

Pacing
Safety
Location
Coping strategies

Question 11

Effects of exercising in the heat?

Answer 11

Redistribution of blood flow
Substrate depletion
Hyperthermia
Hypohydration

Question 12

Define hyperthermia?

Answer 12

An increase in core body temperature

Question 13

Define hypohydration?

Answer 13

Low body water

Question 14

Nutritional considerations for exercising in the heat?

Answer 14

CHO
Fluid
Ice slurry
Glycerol
Energy expenditure
Energy intake
Caffeine
Protein
Creatine
BCAA
Paracetamol

Question 15

The mechanistic effect of increase carbohydrate intake on fluid balance? (Reviewed by Febbraio 2001)

Answer 15

Reduced blood flow to the muscle
Muscle fibre recruitment
Temperature effects on metabolism
Augmented sympathoadrenal response
Reduced muscle water -> reduced glucose transport and glycogenolysis

Question 16

Physiological responses of acclimation?

Answer 16

Increased total body water due to secretion of arginine vasopressin (AVP) and aldosterone
Plasma volume expansion -> increased total intravascular protein causing movement of fluid from interstitial to intravascular space
Increased sweat loss
Increased sweat sodium concentrations

Question 17

The effect of branch chain amino acids on performance in the heat? (Cheuvront et al. 2004; Hobson et al. 2013)

Answer 17

Ingestion of BCAA’s or trypophan depletion can increase the ration of BCAA:fTRp and decrease serotonin
No effect on performance in the heat

Question 18

What are the thermoregulatory responses to the cold?

Answer 18

Vasoconstriction in the skin blood vessels redistributes blood flow and decreases heat loss to the environment
Non-shivering thermogenesis
Shivering

Question 19

Define non-shivering thermogenesis?

Answer 19

Brown adipose tissue generates heat through chemical reactions

Question 20

What is shivering?

Answer 20

When skeletal muscles are activated, which increases metabolism and heat production

Question 21

How much can shivering increase heat production?

Answer 21

five times

Question 22

What are the behavioural responses to the cold?

Answer 22

Hot drink

Increase clothing

Question 23

Energy balance in the Scott Expedition? ( Halsey & Stroud 2012)

Answer 23

Energy expenditure increases in the cold
Over time, with insufficient calorie intake and higher energy expenditure, the had a negative energy balance resulting in weight loss

Question 24

The effect of the cold on water loss?

Answer 24

Cold-induced diuresis -> vasoconstriction will increase BP -> increase urine output
Blunted thirst response
Respiratory losses

Question 25

Define the effect of cold-induced diuresis?

Answer 25

Vasoconstriction -> increase BP -? decrease AVP secretion -> increase urine output -> possible hypohydration

Question 26

What are the acute physiological responses to altitude?

Answer 26

``` Increase ventilation Increase HR Decreased SV Increased CHO use diuresis ```

Question 27

What are the chronic physiological responses to altitude?

Answer 27

Increased production of erythrocytes Decreased muscle mass Decreased body mass

Question 28

The effect of altitude on energy expenditure?

Answer 28

Energy expenditure increased typically resulting in weight loss At 4300m increase 10-17% (Butterfield 1999; Mawson et al. 2000) Appetite suppression (Wasse et al. 2012)

Question 29

What are the effects of altitude on fluid balance?

Answer 29

Altitude-induced diuresis Reduced thirst Increase respiratory fluid loss through increased ventilation and reduced humidity

Question 30

What is the role of hepcidin?

Answer 30

Controls iron turnover | Increased hepcidin decreases iron production

Question 31

The effect of altitude on haemoglobin mass?

Answer 31

Altitude increases haemoglobin mass by 1%