Exam 3 KIN 312 (ch 12, 13)

ch 13: extreme environments... ch

core temperature

• internal or deep temperature

• 98.6 degrees F

skin temperature

• “shell or shield”

• 91.4 degrees F

upper and lower pain thresholds are ____ degrees F

109.4 and 50 F

alternative methods of temp collection

• oral

• rectal

• core

• eardrum

oral temp

most common, least accurate

rectal temp

most consistent, least responsive to acute changes

core temp

eardrum temp check

temp of hypothalamus/brainstem

lowest temp is at end of the ____, and ___ signals and increased _____

night… increase… wakefulness

maximal temp is in the ___

afternoon

core temp increases by about

1 degree F (following female ovulation)… useful to track daily to estimate cycle

convection

• transfer of heat and air

• pulls heat away from around the body

• greater wind= greater transfer

• faster the air/water flow—> greater the heat loss

conduction

• transfer of heat between twp solid objects

• air temp around bodies of water

radiation

• transfer of heat via infared radiation

  • sun’s heating

  • warmer environment than skin—> body absorbs

  • colder—> loses

• regulated by skin blood flow… constricting + dilating skin vessels

evaporation

• body moves water secreted by sweat glands to surface to evaporate

• produces cooling effect

• 80% of heat lost through sweating

• determining factor = air temp and humidity

Heat dissipation

• competition between muscles and skin for blood flow

• back and chest have earlier onset of sweating

where does sweat come from?

• comes from liquid component of your blood**

  • plasma

increased sweating =

decreased blood volume= less blood pumped

thermal gradient between core and skin encourages

blood flow to be cooled

most cooling mechanisms occur via

skin

if we continue to get hotter…

• skin temp begins to rise

• gradient decreases

• core temp begins to rise

cooling methods work to cool ____ then ____

skin… core

high vo2 max + high blood volume =

high plasma volume (which =) lots of volume to sweat

acclimization

gradual increase in exercise duration and intensity (12 weeks) in environment to decrease likelihood of heat injury

sauna usage acclimization

• 180-190 F optimal

• uncomfrotable amount of time

• infared is useless… not hot enough/ not enough support

when cold blood flow does…

redirect blood flow to cold

muscle shivering leads to

• increase in metabolic heat production

• more body fat = delayed shivering

who is best suited for cold?

• bigger body size and fat

• fat produces less heat than muscle, but has higher insulation factor

• higher metabolic rate = greater heat production

death zone is above

• above 26,000 ft

• oxygen pressure insufficient to sustain life

humans are ____therms

homeotherms

homeotherm

body temp is regulated to stay close to a set point

• 98.6 F or 37 C

exercise muscle contraction = increase in

body heat

heat injury occurs when body temp exceeds… degrees

105 degrees F

most important means of body heat loss during exercise is

evaporation

clothing for hot environment

• minimize amount you wear

• maximize exposed surface area for evaporation

• clothes should be light weight, light colored, move freely, absorb moisture… cottons + linens

heat injury

occurs when the heat load exceeds body’s ability to regulate body temperature

heat cramps

characterized by muscle spasms or twitching of the limbs

heat exhaustion

results in general weakness, fatigue, a drop in blood pressure, blurred vision, occasionally loss of consciousness, profuse sweating from pale clammy skin

heat stroke

life- threatening emergency

• person stops sweating, skin becomes hot and red

• signs: involuntary limb movement, seizures, diarrhea, vomiting, and rapid, strong heartbeat

drink approximately 16 oz (2 cups) fluid about __ hrs before workout

2 hours

drink about 4-8 oz every ____ min during exercise, regardless of if you feel thirsty

10-20 min

water best for ___ duration, sports drinks may be better for ___ duration

short…longer

hypothermia

significant decline in body temp due to exposure to cold

long periods (1-4 hrs exercising in the cold can lead to

hypothermia

clothing in cold environment

• trap just enough heat during exercise to maintain normal body temp, without overheating

• layering (especially upper body) is CRITICAL for maintaing body’s core temp

• several layers provide more effective insulation than bulky coat

base layer clothing

• removes moisture form skin, moves it to next (wicking)

• avoid cotton

middle layer clothing

• further insulates body, wicks moisture outward

• often heavier than base layer

• only worn in very cold condition

outer layer clothing

• protects from wind/water

• hats, scarves, gloves protect extremities from frostbite and keeps heat from escaping

at higher altitudes a (lower/higher) barometric pressure limits amount of ____ transported in the blood, decreasing ____ and exercise tolerance

lower… oxygen… vo2 max

acute mountain sickness (AMS)

• occurs at altitudes above 8,000 feet

• affects about 20% ppl exercising at/ above 8000 ft

• affects up to 80% who fly into high elevation

AMS symptoms

• severe headaches

• nausea

• weakness

• dizziness

if acute mountain sickness is not corrected it can

cause fluid to collect in brain or lungs… life threatening condition

avoiding AMS

• ascend slowly

• if above 10,000ft , increase altitude by no more than 1,000 ft per day

• sleep at lowest elevation possible

• eat high carb diet

major forms of air pollution

• ozone

• carbon monoxide

ozone

gas produced from sunlight and car exhaust

• extrememly irritating to lungs + airways

• causes chest tightness, coughing, headaches, nausea, throat, eye irritation, bronchoconstricition

• may trigger asthma attacks

carbon monoxide

gas from fossil fuels and cigarette smoke

• reduces blood’s capacity to carry oxyen to body and muscles

• high traffic environments = serious health threat

main causes of exercise injury

• improper training techniques

• inadequate shoes

• alignment abnormalities in legs and feet

• improper exercise techniques

tendonitis

swelling in the tendon… prevention: avoiding joint overuse, proper exercise technique

ligament sprains

excessive force applied to a joint

prevention: use a brace/refrain from high stress activities

torn cartilage

cause: high force or unusual movements

prevention: limit high stress activities on joint/avoid movements outside normal range of motion

common conditions and injuries

• delayed onset muscle soreness

• muscle strains

• tendonitis

• ligament sprains

• torn cartilage

• patellofemoral pain syndrom e(PFPS)

• shin splints

• stress fractures

cryokinetics

rehab technique that incorporates alternating periods of treatments, using ice, exercise, rest

RICE method

• rest

• ice

• compression

• elevat