this is exercise physiology lecture class

1. Chapter 6: Exercise and environnemental
conditions
6.1. Exercise in the Environment Extremes
•Environmental conditions, Climate, and weather are terms
commonly used in describing various external impacts on
sporting events and athletes:
•The environmental conditions may be any outdoor or
indoor condition that potentially affects the performance of
the athlete.

2. The environment will include weather conditions, the
physical nature of the venue, such as topography or altitude,
as well as man-made factors such as pollution, traffic that
impacts on events such as cycling, or noise, such as stadium
noise.
•Climate is the recorded and tabulated weather data over a
period of time.
•This factor is used to determine the climatic regions of
Earth, those places that are said to share a common pattern
of weather.

3. Weather is the state of atmosphere in a given place on
Earth in the particular time;
•Weather includes the temperature, moisture, wind, cloud
cover, presence of phenomena such as storms, and
barometric pressure readings.
•Weather by nature an indication of present atmospheric
events for the short term.

4. 6.2. Exercise in the Heat
•Hyperthermia is a condition in which body temperature
increases above normal.
•The key to managing hyperthermia is to cool the body.
–by moving the athlete to a shaded area,
–removing any unnecessary clothing,
–applying cool water to the extremities,
–fanning the athlete, and
–giving the athlete cool water to drink.

5. Water Loss in the Heat
•Dehydration induced by a few hours of intense exercise in the heat
•often reaches in the level of impede heart dissipation and severely
confront cardiovascular function and exercise capacity. Sport
drinks which contain various levels of fluid, electrolytes and
carbohydrate to decrease the level dehydration
• An isotonic drink- is easily absorbed and quickly leaves the
stomach, to ensure optimal efficiency and comfortable digestion.
• A hypotonic drink -is less easily absorbed than an isotonic
drink, but may be useful in very hot weather.
• A hypertonic drink -is too concentrated and take too long to
leave the stomach, which may cause digestion issues, potentially
causing dehydration through a demand for water in the stomach
to dilute the concentration.

6. Heat is removed from the body by a combination of the following
mechanisms:
1. Conduction
•Heat exchange by transfer of heat between molecules that are
indirect contact with one another.
•These molecules can be present in the form of liquid, solid, or
gas.
2. Convection
•Once air molecules in contact with the skin are heated via
conduction,

7. Convection describes that the process by which the
warm air molecules are replaced by cooler air
molecules.
3. Radiation
•Heat loss by radiation describes the release of
electromagnetic waves to hot solid objects in our
surrounding environment.
•In the same way our bodies receive heat from the sun
through radiation, our bodies release heat to our
surroundings.

8. 4. Evaporation: The major mechanism by which heat is
removed from the body during exercise is evaporation.
•Water is continually vaporizing from the skin and
respiratory passages, thus transferring heat to the
environment.
•Evaporation of sweat has a cooling effect on the skin,
which in turn cools the blood in the skin via conduction.
5. Respiration
•Takes place when inspired, cooler air is raised to the body
temperature in the lungs and heat is lost through
respiration.

9. Heat-related illnesses
•Heat-related illnesses are typically classified, in
increasing order of severity, as heat cramps, heat syncope
or heat exhaustion and heat stroke:
Heat Cramps
•Painful cramping of abdominal and extremity muscles
• Elevated body temperature

10. Management: Heat Cramps
–Ending of activity
–Gentle passive stretching of affected muscles
–Drinking cool water or an electrolyte solution (low in sugar)
–For severe symptoms treat as heat exhaustion
Heat Exhaustion/Heat Syncope
(Can progress rapidly to heat stroke unless managed Properly)
–Exhaustion, nausea, vomiting and dizziness
–Weakness, fatigue and fainting
–Elevated body temperature

11. Management of Heat Syncope and Heat Exhaustion
-Remove the athlete from the hot environment and rest in a cool,
shaded area
–Remove restrictive clothing
–Give fluids orally, if the athlete is conscious
–Apply active cooling measures such as fun or ice towels if the
core temperature is elevated
–Refer to a physician to assess the needs of fluid/electrolyte
replacement and further medical attention, especially if nausea
and vomiting are present.

12. Heat Stroke
Acute medical emergency due to thermoregulatory failure
–Nausea, seizures, disorientation and possible unconsciousness or
coma
–Hot, dry skin and high body temperature (40°C/105°F)
•Management of Heat Stroke
–Medical emergency
–activate ems (medical emergency service) immediately
–Monitor core body temperature and lower it as quickly as
possible
–Remove as much clothing as possible

13. –Immersion in an ice bath has been shown to be
the best method to decrease core body
temperature
–Apply ice packs in the armpits, groin and neck
areas
–Continue cooling efforts until EMS arrives

14. 6.3. Exercise in the Cold
•Hypothermia is a condition in which body temperature
decreases below normal.
•The key to managing hypothermia is to warm the body.
This can be accomplished by
–removing the athlete from the cold climate,
–removing wet or cold clothes,
–applying warm clothes or blanket, and
–providing warm liquid to drink.

15. Cold environment problem
•Frostbite – it occurs when skin tissue and blood vessels are
damaged from exposure to temperatures below 32°F.
•Frostbite most commonly affects the toes, fingers, earlobes,
chin, cheeks, and nose - the body parts that are often left
uncovered in cold temperatures.
•Frostbite can occur gradually or rapidly.
•The speed which frostbite progresses will depend on how cold
or windy and the duration of exposure to those conditions.

16. Treatments for cold weather illness
•Restore Warmth
–Get the person to a warm place.
–Unless absolutely necessary, the person should not walk on
frostbitten toes or feet.
–Do not re-warm the skin until you can keep it warm.
Warming and then re-exposing the frostbitten area to cold air
can cause worse damage.
–Gently warm the area in warm water or with wet heat until
the skin appears red and warm.
–If no water is nearby, breathe on the area through cupped
hands and hold it next to your body.
–Do not use direct heat from heating pads, radiator, or fires.
–Do not rub or massage the skin or break blisters.

17. Bandage the Area
–Loosely apply dry, sterile dressings.
–Put gauze or clean cotton balls between fingers or toes to
keep them separated.
•Follow Up
–Once you get medical care, the next steps depend on the
particular case.
–The doctor may administer medication for pain or
intravenous fluids if the person is dehydrated.
–The person may be hospitalized for a few days.

18. High Altitude
•What's high altitude?
•It's considered to be between 5,000 and 11,500 feet (1,524
and 3,505.2 m) above sea level.
•Very high altitude is any altitude between 11,500 and
18,000 feet (5,486.4 m), and extreme altitude is anything
above 18,000 feet.
•As height is gained above this altitude the density of oxygen
in the atmosphere decreases and the density of carbon
dioxide in the atmosphere increases.

19. •Normoxia - The normal oxygen content reaching tissues and
organs at sea level (with 21% O2 in the air, with a sea-level
atmospheric pressure (driving pressure) of 760 mmHg).
•Hyperoxia - A condition characterized by greater oxygen content
of the tissues and organs than normally exists at sea level (i.e.
having someone breathe air that contains greater than 21% O2
contents).
•Hypoxia - A deficiency of oxygen that normally reaches the
tissues of the body, such as at altitude (generally considered less
than 21% O2 contents or at a reduced atmospheric pressure such as
at altitude).

20. Symptoms indicate altitude illness
–Headaches both while exercising and at rest that will not go
away if Aspirin is taken.
–Breathlessness at rest, and extreme fatigue after exertion.
–Decrease in appetite commonly accompanied by attacks of
nausea.
–High altitude also triggers an increase in our heartbeat,
breathing and urination.
–A resting heart-rate of more than 100 beats per minute.
–Irritability and/or mood swings.

21. Chapter 7: Body Response to Exercise
•Exercise is a single acute bout of bodily exertion or
muscular activity that required an expenditure of energy
above resting level and generally resulted in voluntary
movement.
•Exercise disrupts the Homeostatic state of the body.
•These disruption or change the body’s response to
exercise depends up on
–Exercise modality, Intensity, characteristics of exerciser
and whether the test is standard or field based task.

22. Metabolic responses to exercise
•When you begin to exercise your body must
immediately adjust to the change in activity level.
•Energy production must increase to meet demand with
changes to the predominant energy system and
•fuel source occurring throughout the exercise in order to
maintain the required level of performance.

23. Physiological bases of Stress: Neuro-hormonal Control
•Stress – The state manifested by the specific syndrome that
consists of all the non-specifically induced
–changes within a biological system,
–a disruption in body homeostasis and
–all attempt by the body to regain homeostasis.
•There are two complementary, and often overlapping,
physiological pathways through which the body responses to
all stressors;
–the nervous system and
–the hormonal system.

24. Warning symptoms of overtraining
•Performance related
–Consistent decrement of performance
–Persistent fatigue and sluggishness that leads to several days
of poor training.
–Prolonged recovery from training sessions or competitive
events.
–Reappearance of already corrected errors.
•Physiological related
–Decreased maximal work capacity.
–Increased disruption of homeostasis at submaximal work
load

25. Physiological related
–Headaches or stomach-aches out of proportion to life event
–Insomnia /sleeplessness, sleep disorder/
–Persistent low grade stiffness and soreness of the muscles
and joints
–Frequent sore throated, and cold sores
–Diarrhea or constipation.
–Loss of appetite; loss of body weight and muscle mass when
no conscious attempt is being made to diet or when weight
loss is undesirable.
–An elevation of heart rate approximately 10% in morning
taken immediately awakening amenorrhea.

26. Psychological/Behavioral
–Feeling of depress
–General apathy, especially towards previously
enjoyable activities.
–Decrease instability or mood change.
–Difficult concentration.
–Loss of competitive drive or desire.

27. 4.1. Responses to Anaerobic Exercise
•Meet the sudden higher energy demand, i.e. stored ATP.
•ATP-PC system can only last 8-10 seconds before PC stores are
depleted.
•The lactic acid system (Anaerobic glycolysis) then take over as
the predominant source of energy production.
•Oxygen is not available at a fast enough rate the production of
lactic acid will reach to Lactate threshold.
•Muscles begin to fatigue when ATP resynthesizes can no longer
match demand.

28. 4.2. Responses to Aerobic Exercise
•Due to oxygen being present aerobic metabolism is
used.
•Continued low to moderate intensity exercise is
then fuelled by carbohydrate and fat stores using
aerobic metabolism.
•As carbohydrate stores get lower, the body has to
rely more and more on fat stores.

29. Oxygen Debt and Recovery
•When you have a short intense burst of exercise such as sprinting
you generate energy anaerobically or without oxygen.
•When you stop exercising you are still breathing heavily.
•The difference between the body required oxygen and what it
actually managed to take in during the sudden sprint is called
oxygen deficit.
•When you stop sprinting and start to recover you will actually
need more oxygen. This is called Excess Post Exercise Oxygen
Consumption.

30. So why does it take more oxygen to recover then?
–You needed to replace the oxygen the body needed but
couldn’t get (oxygen deficit).
–Breathing rate and heart rate are elevated (to remove
CO2) and this needs more oxygen.
–Body temperature and metabolic rate is increased and
this needs more oxygen.
–Adrenaline and Noradrenaline are increased which
increases oxygen consumption.

31. •Notice the area of oxygen debt is greater than the area of
oxygen deficit for the reasons stated above.

32. 4.3. Short term physiological response
•When we begin to exercise the body has to respond to
the change in activity level in order to maintain a constant
internal environment (homeostasis).
Circulatory System
•The release of adrenaline (often before exercise even
begins) causes the heart rate to rise
•Increases Cardiac Output
•Venous return increases due to the higher Cardiac
Output and the skeletal muscle pump and respiratory
pump

33. •Increases in Lactic Acid (produced during the early
anaerobic phase of exercise), Carbon Dioxide (due to
increased rates of energy production) and temperature.
•Oxygen levels within the blood decrease which causes
increased diffusion at the lungs.
•Blood pressure increases, thus increasing flow rate and the
speed of delivery of O2 and nutrients to the working
muscles
•Vasodilation and vasoconstriction ensure blood is directed
to areas that need it (muscles, lungs, heart) and away from
inactive organs

34. Respiratory System
–Changes in the concentration of CO2 and O2 in the blood are
detected by the respiratory centre which increases the rate of
breathing.
–The intercostal muscles, diaphragm and other muscle which
aid the expansion of the thoracic cavity work harder to further
increase the expansion during inhalation, to draw in more air.
Muscles
–The higher rate of muscle contraction depletes energy stores
and so stimulates a higher rate of energy metabolism.
–The body’s energy stores are slowly depleted
–Myoglobin releases its stored Oxygen to use in aerobic
respiration. O2 can now be diffused into the muscle from the
capillaries more quickly due to the decreased O2 concentration
in the muscle.

35. 4.4. Long term physiological response
•Regular exercise results in adaptations to the circulatory,
respiratory and muscular systems in order to help them perform
better under additional stress.
Circulatory System
–The cardiac muscle surrounding the heart hypertrophies, resulting
in thicker, stronger walls and therefore increases in heart volumes.
–The more blood pumped around the body per minute, the faster
Oxygen is delivered to the working muscles.
–The number of red blood cells increases, improving the body’s
ability to transport Oxygen to the muscles for aerobic energy
production.

36. •The density of the capillary beds in the muscles and
surrounding the heart and lungs increases as more branches
develop.
•This allows more efficient gaseous exchange of Oxygen and
Carbon Dioxide.
•The resting heart rate decreases in trained individuals due to
the more efficient circulatory system.
•The accumulation of lactic acid is much lower during high-
levels activity, due to the circulatory system providing more
Oxygen and removing waste products faster.
•Arterial walls become more elastic which allows greater
tolerance of changes in blood pressure.

37. Respiratory System
•The respiratory muscles (Diaphragm/intercostal) increase
in strength.
•This results in larger respiratory volumes, which allows
more Oxygen to be diffused into the blood flow.
•An increase in the number and diameter of capillaries
surrounding the alveoli leads to an increase in the efficiency
of gaseous exchange.

38. Muscle
•Increased numbers of mitochondria (the cells powerhouse)
means an increase in the rate of energy production.
•The muscles, bones and ligaments become stronger to
cope with the additional stresses and impact put through
them.
•The amount of myoglobin within skeletal muscle
increases, which allows more Oxygen to be stored within
the muscle, and transported to the mitochondria.
•Muscles are capable of storing a larger amount of
glycogen for energy.
•Enzymes involved in energy production become more
concentrated and efficient to aid the speed of metabolism.