environmental exercise physiology

Question 1

what is thermoregulation?

Answer 1

the body’s ability to constantly balance heat production and heat loss

Question 2

what are thr two sources of heat?

Answer 2

internal = metabolism

extermal = environmental

Question 3

how does metabolism generate heat?

Answer 3

whenever we break bonds apart for fuel, we generate ATP = 60% loss in form of heat

during exercise, the longer/harder you work out, the more oyur core temperature will go up

Question 4

what happens when the temperature outside is warmer than inside the body?

Answer 4

it causes core temperature to go up if higher than 40 degrees

can also be road temperature

Question 5

what are ways for us to lose heat?

Answer 5

1) vasodilation near the skin
2) conduction
3) convection
4) radiation
5) evaporation

Question 6

what heat loss sources want to have blood vessels close to skin to make them more efficient?

Answer 6

conduction

convection

radiation

Question 7

what is conduction?

Answer 7

heat transfer through physical contact

Question 8

how can you cool an athlete through physical contact?

Answer 8

cold towels

mist

cool vests

**not best to dump water on head because water ill soak your clothing, making it more humid = hotter**

Question 9

what is convection?

Answer 9

heat we produce warms the air close to body, airflow moves warm air away

Question 10

how can we cool down via convection?

Answer 10

using a fan or going to a place with a breeze will quickly remove the heated and humidified air close to body

Question 11

how do we cool via radiation?

Answer 11

reduce the effect of radiation (shade)

allow heat to esape (radiate away)

AKA less clothing

Question 12

what is the difference of sweating and evaporation?

Answer 12

evaporation happens after athlete sweats… sweat needs to evaporate in order to cool us down

Question 13

what is the greatest source of heat loss when active?

Answer 13

evaporation

Question 14

why can we only cool from evaporation if we’re hydrated?

Answer 14

if body is dehydrated, you will not sweat = no evaporation

Question 15

what is the most effective way to lose heat at rest?

Answer 15

radiation

Question 16

explain heat loss steps

Answer 16

the harder and more muscles you’re using, the faster the core temperature rises =

vasodilation close to skin =

radiation, conduction, and convection is more efficient to ramp up evaporation at same time =

core temperature back down to 37 degrees

Question 17

what is the effect on evaporation when there’s humidity?

Answer 17

it it’s humid outside and you sweat, the air won’t be able to accept anymore moisture = no evaporation

Question 18

what is the main receptor for our body’s thermostat?

Answer 18

central thermoreceptors = anterior hypothalamus

• measures temperature of the blood

peripheral thermoreceptors = on skin

• measures temperature around you

Question 19

what are some thermoregulation effectors?

(what anterior hypothalamis does)

Answer 19

1) eccrine (ramp up) sweat glands
2) smooth muscle in blood vessels close to skin
3) skeletal muscle
- cns telling you not to exercise because core temp. already rising
4) endocrine glands (thyroxin)

Question 20

explain a thermoregulation feedback loop

Answer 20

1) increased blood/internal temperature
2) hypothalamus detects rise
3) vasodilation occurs in skin blood vessels
4) sweat glands become more active
5) body temperature decreases

Question 21

what is a physiologic response to blood when we exercise in heat?

Answer 21

redistribution of blood

• redirection near skin for cooling

drop in aerobic performance due to blood going from muscles to skin

Question 22

what is a physiologic response to energy systems with exercising in heat?

Answer 22

less access to o2 = slight drop of o2 in muscles

demand for glycogen increases due to lack of o2

earlier fatigue

Question 23

what is a physiologic response to fluid balance when exercising in heat?

Answer 23

higher by-product concentrations

ex: lactate

Question 24

how do we lose electrolytes with training?

Answer 24

body starts manipulating hormone levels

(aldosterone)

the more fit you are, the less electrolytes we lose in our sweat

Question 25

what are heat related disorders?

Answer 25

1) heat cramps
2) heat exhaustion
3) heat stroke

Question 26

what are heat cramps and how do we treat them?

Answer 26

imbalance of sodium and potassium and sometimes ions inside muscle

ex: sodium wants to regulate water levels outside cell, potassium wants to do opposite.. when sweating we lose a lot of water from outside of cell = sodium levels in muscles drop = cramping in muscles
treatment: cool & fluid and electrolytes

Question 27

what is heat exhaustion and how do we treat it?

Answer 27

full body effect

• after cramps
• dizzyness/fainting
• ecessive fluid loss
• ramp up HR = tiring to body

treatment:

• cool
• raise feet
• electrolytes/I.V

Question 28

what is heat stroke and how do you treat it?

Answer 28

high core temp

• dry skin due to dehydration
• rapid pulse for cardiac output
• unconsciousness since the body is pushed so out of homeostasis that it shuts down as a last defence mechanism

treatment:

• cool immediately
• medical attention

Question 29

what are some exercise recommendations to prevent hyperthermia?

Answer 29

1) be aware of humidity
2) be aware of temperature
3) ensure hydration
4) wear proper clothing

Question 30

what is the purpose of heat acclimatization?

Answer 30

get to place of competition a couple days earlier to adapt

adaptations that occur:

1) brain ignores inhibitory sensory feedback
2) increased sweat rpoduction
3) less electrolyte loss
4) increased glycogen storage