Guided Notes:
(A) Environment Factors and Physical Performance (3 lessons + h/w)
1.
Body core temperature - what is it? (A.2.2)
2.
Explain the relationship between cellular metabolism and the production of
heat in the human body (A.2.1)
3.

Include information on how we get our energy from food and it is
chemically released within our cells.

Such energy is stored in bodily tissues in the form of ATP + ATP
resynthesis (v.v. briefly)

Humans require energy for (1) heat production and (2) muscle
contraction

Heat is the byproduct of Metabolism; along with the effect on heat
levels when metabolism increases or decreases
Explain how the body thermoregulates in hot and cold environments Conduction, Convection, Radiation, Evaporation (A.2.3) - see Instant Notes
Handouts & Revision Guide Note:
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Guided Notes:
(B) Environment Factors and Physical Performance
Cold Temperature (link with IA Coursework): Essentials for Ex Physiology by
Katch, McKardle & Katch Pg 493 + Pg 44 A2 PE Revision Guide
4.
Outline the principal means by which the body maintains core temperature in
cold environments; you must include information on (1) Shivering, (2) Nonshivering thermogenesis (protein in brown adipose tissue & movement of
electrons which creates heat) (3) Peripheral vasoconstriction (shunting of
blood away from the skin to the core): (A.2.11)
5.
Discuss the physiological responses of the body when exercising in the cold:
you must focus on (1) muscle function and (2) metabolic response (A.2.15)
6.
Explain why swimming in cold water represents a particular challenge to the
body’s ability to thermoregulate (A.2.14) [see Pg 187 IBO SEHS]
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7.
we lose body heat and become hypothermic (at a rate proportional to
the thermal gradient and the duration of exposure).
the effect of cold water on body heat loss is increased because of
greater convective heat loss.
Swimming at high speeds increases the metabolic rate of the swimmer
and this helps to compensate for the increased heat loss
Discuss the precautions that should be taken when exercising in the cold
(A.2.17)
a. Clothing – principle barrier
i. the amount of insulation offered by which is measured in a
unit called a clo (1 clo=0.155m2 KW -1)
ii. Insulating effect of clothing: type of clothing, importance of
layers in trapping air movement around the body
iii. Dangers of overdressing - due to increase in heat production
and sweat response
iv. Importance of scarf/balaclava (warming up and moistening
incoming breath) and the effect on the body of inhaling cold
dry air.
b. Importance of rehydration with regard to your bodies ability to thermo
regulate
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Guided Notes:
(C) Environment Factors and Physical Performance
Hot Conditions Essentials for Ex Physiology by Katch, McKardle & Katch Pg 493
8.
Describe the formation of sweat and the sweat response (A.2.5) – see DSt
handout
9.
Discuss the physiological responses that occur during prolonged exercise in
the heat (A.2.6): Limit this to:
a. Sweating – what are the effects of the following on the body?
i. A loss of fluid, (dehydration) loss of body mass, decrease
plasma volume, altered electrolyte balance which will result in
reduced effectiveness of nerve impulses to working muscles
and in turn loss of coordination, decreased SV, venous return,
results in a reduced blood flow to working muscles and
therefore decreases the oxygen available to working muscles in
addition to reducing the removal of fatiguing by-products;
b. cardiovascular response (cross reference with 2.2.8 cardiovascular
drift)
i. an increase of body temperature results in a lower venous
return to the heart, a small decrease in blood volume from
sweating. Arterial blood pressure also declines
ii. include reference to blood viscosity – thickening of the blood
& small decrease in blood volume (SV) makes it harder for the
heart to maintain the same cardiac output
iii. These responses are due to the need to remove excess heat
produced by active tissues from deep in the body (core) to the
skin where it can be released at body’s surface. Blood is
redirected to the skin through vasodilation of blood vessels.
iv. The heat is moved by the blood during vasodilation of blood
vessels directly underneath the skin. Peripheral blood flow to
the skin increases to transport metabolic heat from exercise and
less blood is available for active muscles and in turn less
oxygen to working muscles + increase in lactic acid levels
c. energy metabolism – active muscles generate large amount of heat as
a by-product of elevated levels of metabolism.
i. Muscles work harder due to the reduced muscle blood flow
(dehydration/increase viscosity of the blood) in high
temperatures - results in increased glycogen breakdown in the
muscle and higher levels of muscle and blood lactate (oxygen
debt) in comparison to the same exercise performed in a cooler
environment
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Guided Notes:
Acclimatization – Hot Environments
10.
Describe the steps an athlete preparing for an event in a hot environment
might take to acclimatize (to heat stress) prior to and on the day of the
competition (A.2.9)
Leading up to the competition ie Olympics, world cup
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Pre Competition preparation
How many days does it take to acclimatize to new climates?
Intensity of training sessions
Timing of training sessions
How can athletes ensure in the lead up to the competition their body
weight is within 1% of their normal body weight during the day of the
competition?
What type of clothing should athletes be wearing?
How can athletes/coaches monitor the health and performance of their
athletes during and after training sessions?
On the day of the competition:
 What type of clothing should athletes be wearing?
 When and how would athlete’s warm-up in climatic environments?
 How can athletes ensure their body weight is within 1% of their
normal body weight during the day of the competition
 Why is it important that athletes know their own sweat rate?
 How can ice vests help cool athletes down?
 What else can athletes do to cool down?
11.
Discuss the positive physiological and metabolic adaptations that occur with
heat acclimatization (A.2.10). Include:

increased sweat response = onset of sweat, diluted sweat, electrolytes,
nerve impulses to working muscles, decreased drive for blood flow to
skin and more blood to working muscles

increased plasma volume = blood flow (increase SV) and oxygen
levels, core body temp

reduced rate of muscle glycogen utilization – blood supply, SV &
cardiac output

Increased (i) Haemoglobin concentration, (ii) muscle myoglobin in
muscle cells, (iii) muscle cell mitochondria and (iv) oxidative enzymes
in mitochondria
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Guided Notes:
(D) Environment Factors and Physical Performance
Handouts
1. Why the body surface area-to body mass ratio is important in terms of heat
preservation (A.2.12) + Pg 184 IBO SEHS
2. Describe the formation of sweat and the sweat response (A.2.5)
3. Discuss the significance of humidity and wind in relation to body heat loss
* windy – sweat is evaporated very quickly, cools very effectively
* humid –higher levels of humidity lead to lower levels of evaporation &
less effective body heat loss (A.2.4)
4. Outline the importance of wind-chill in relation to body heat loss (A.2.13)
Pg 511 Katch “A chill factor created by the increase in the rate of heat loss
via convection and conduction caused by wind”
Partner Work
5. Discuss the health risks associated with exercising in the cold, including cold
water :only focus on (1) Hypothermia & (2) Frostbite; you must look at
Explanation Causes, Symptoms, Treatment & Prevention (A.2.16)
6. Discuss the health risks associated with exercising in the heat (A.2.7) &
Outline what steps should be taken to (1) prevent and (2) treat heat-related
disorders (A.2.8)
Heat related disorders include (symptoms/causes)

Heat Cramps – prevention & treatment

Heat exhaustion - prevention & treatment

Heat stroke (also called sun stroke) - prevention & treatment
7. What steps can an athlete take on the day of performance, other than wearing
an ice vest to prevent heat related disorders?
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Guided Notes:
windy – sweat is evaporated very quickly, cools very effectively;
humid – air saturated with moisture / higher levels of humidity lead to lower levels of
evaporation / less effective body heat loss; [2 max]
in both, sweat is produced in response to the build up of heat in the body to bring
about heat loss (due to exercise and environment);
it is essential for the body to maintain body temperature within a narrow range /
homeostasis;
evaporation of sweat during exercise is the main source of heat loss;
high core body temperatures are potentially dangerous to health;
high core body temperatures can be detrimental to performance;
if fluid is not ingested to replace sweat loss it will lead to dehydration;
humid conditions can have a negative effect on performance;
importance of appropriate clothing when running in a hot, humid environment;
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