cardiovascular
respiratory
musculo-skeletal
diet & health
effect of exercise
EFFECTS OF EXERCISE
The effects of exercise on the body
© Copyright Ali Clarke Design 2003
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cardiovascular
respiratory
musculo-skeletal
diet & health
effect of exercise
Contents – Effect of exercise
When you exercise…
Exercise & respiratory system
Exercise & cardiovascular system
Exercise & musculo-skeletal system
Preventing overheating
Food & drink requirements
Smoking & fitness
Summary
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cardiovascular
respiratory
musculo-skeletal
diet & health
effect of exercise
When you start to exercise…
 The muscles must be kept supplied with oxygen to fuel
muscle contractions & allow movement
 This involves taking more oxygen into the body by
breathing more quickly
 The heart also beats faster to pump oxygenated blood
around the body more rapidly
 Muscle contractions generate a lot of heat, which must
be removed to prevent the body from overheating
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cardiovascular
respiratory
musculo-skeletal
diet & health
effect of exercise
When you train regularly…
 Changes occur in your heart, lungs, muscles & bones
as you becomes fitter
 They allow your body to adapt more quickly to exercise
& to make a faster recovery when you finish a training
period
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cardiovascular
respiratory
musculo-skeletal
diet & health
effect of exercise
Immediate effect of exercise
Respiratory
 Breathing rate 
Cardiovascular
 Pulse rate 
 Air inhaled 
 Blood Pressure 
 Blood flow through Lungs   Volume of blood pumped 
 O2 collected
keeps muscles supplied with O2
 CO2 removed
removes waste CO2 from muscles
Musculo-skeletal
 O2 demand of muscles 
 Heat is generated
- removed by sweating
& flushing of skin
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cardiovascular
respiratory
musculo-skeletal
diet & health
effect of exercise
Effect of regular exercise over time
Respiratory
 Respiratory muscles
stronger & more efficient
  vital capacity
  growth of capillaries
around alveoli
 Allow you to train harder
& longer
Cardiovascular
Musculo-skeletal
 Heart enlarges slightly

 Red blood cells number 
 Artery walls  elasticity
  growth of capillaries around
Muscles, tendons grow  strength
muscles
 Muscles more efficient at using O2
 Ligaments  strength
 Range of movement in joints 
 Bones  strength
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cardiovascular
respiratory
musculo-skeletal
diet & health
effect of exercise
Exercise & respiratory system
 Breathing rate increases
 Depth of breathing increases; i.e. volume of each
breath increases (maximum possible = vital capacity)
 More blood flows through the lungs
 These changes allow
 Increased amounts of oxygen to be collected to power the
exercising muscles
 Increased amounts of waste carbon dioxide to be removed
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cardiovascular
respiratory
musculo-skeletal
diet & health
effect of exercise
Exercise & respiratory system
 With regular exercise, the respiratory muscles (diaphragm +
intercostals) become stronger & more efficient at opening
up the chest cavity
 The vital capacity increases, so more oxygen can be taken
in per breath (& more carbon dioxide can be removed)
 New capillaries grow around the alveoli, allowing greater
oxygenation of the blood (& faster removal of carbon
dioxide)
 These changes allow you to exercise more vigorously for a
longer time
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cardiovascular
respiratory
musculo-skeletal
diet & health
effect of exercise
Exercise & cardiovascular system
 Heart beats faster; pulse rate increases
 Greater volume of blood is pumped per heart beat
 Blood pressure rises transiently during exercise
 BP drops back to pre-exercise levels when physical activity ceases
 Blood is diverted away from the major body organs,
except the heart & brain
 Blood flow into the muscles is increased
 Around 20% of blood volume goes to muscles when body is at rest
 This rises to around 90% during vigorous exercise
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cardiovascular
respiratory
musculo-skeletal
diet & health
effect of exercise
Exercise & cardiovascular system
 With regular exercise, the heart grows slightly larger &
its walls become thicker
 This allows the heart to hold more blood & to contract
with greater force
 The body produces more oxygen-carrying red blood
cells
 The artery walls become more elastic & prevent blood
pressure rising too far during exercise
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cardiovascular
respiratory
musculo-skeletal
diet & health
effect of exercise
Exercise & musculo-skeletal system
 The amount of oxygen consumed by the muscles
during exercise increases x70 above resting levels
 As the muscles work they generate heat, warming the
blood
 Contracting muscles squeeze the veins & force blood
back to the heart
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cardiovascular
respiratory
musculo-skeletal
diet & health
effect of exercise
Exercise & musculo-skeletal system
 With regular exercise, the muscles (& tendons) get
bigger, allowing them to contract with greater strength
 Increased numbers of capillaries grow around the
muscles, so more blood can reach them with oxygen
& nutrients
 Muscles become more efficient at using oxygen & can
work harder for longer without tiring
 The body’s maximum oxygen consumption (VO2max)
increases
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cardiovascular
respiratory
musculo-skeletal
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effect of exercise
Exercise & musculo-skeletal system
 Regular exercise also strengthens the ligaments
around a joint, making the joint stronger & more stable
 Stretching movements will also increase the range of
movement of a joint
 The articular cartilage pads that line synovial joints
become thicker, & protect the underlying bones from
mechanical stress
 Bones become stronger
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cardiovascular
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musculo-skeletal
diet & health
effect of exercise
Preventing overheating
 Repeated muscle contractions release a large amount of
heat energy & this must be removed quickly to prevent
the body from becoming overheated
 Thermal sensors in the brain monitor body temperature;
when it rises too high, heat loss mechanisms are put into
operation
 Heat loss is achieved using two main methods;
 Radiation
 Evaporation
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cardiovascular
respiratory
musculo-skeletal
diet & health
effect of exercise
Preventing overheating: radiation
 Heat generated by the muscles is used to warm up the
blood
 Blood is then shunted through vessels close to the skin
surface, which dilate to maximise the volume of blood
passing through them
 The skin appears flushed & feels hot
 Heat radiates from the skin surface into the surrounding
colder air, allowing the body to cool down
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cardiovascular
respiratory
musculo-skeletal
diet & health
effect of exercise
Preventing overheating: evaporation

Heat can also be lost by using heat energy to convert liquid into
vapour, i.e. evaporation


This is more commonly known as sweating

Rising body temperature simulates sweat glands to secrete sweat
onto the skin surface, it is then evaporated using body heat energy
& helps to cool the body

Excessive sweating can lead to loss of body fluid & salt, causing
dehydration & cramping
Sweat is produced by sweat glands present throughout the skin, it
contains mostly water plus a few salts
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cardiovascular
respiratory
musculo-skeletal
diet & health
effect of exercise
Overheating
 If the external environment is either hotter than the
body or is humid, heat loss by radiation & evaporation
will be severely impaired
 Heat exhaustion can occur if an athlete overheats &
collapses following vigorous exercise; it is often caused
by dehydration
 Heat stroke is a potentially fatal condition caused by
prolonged overheating; it is a medical emergency
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cardiovascular
respiratory
musculo-skeletal
diet & health
effect of exercise
Food & drink requirements: water
 A lot of water can be lost from the body during exercise;
 Increased body heat  water lost as sweat
 Increased breathing rate  water vapour lost via lungs
 Dehydration can result in
 Thirst
 Headache
 Dizziness
 Muscle cramps
 To avoid dehydration, it is important to take on adequate
fluids during exercise
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cardiovascular
respiratory
musculo-skeletal
diet & health
effect of exercise
Food & drink requirements: food
 Energy for muscle activity during exercise needs to be
available quickly to avoid muscle fatigue
 The main source of this energy is the carbohydrate storage
molecule glycogen
 Body glycogen stores are limited & are depleted during
exercise; they can take up to 48 hours to be replenished
 Extra carbohydrate must be eaten to replace glycogen
stocks during endurance events, such as football or tennis
matches, distance running, etc.
 E.g. bananas, biscuits, jam sandwiches, dextrose tablets
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cardiovascular
respiratory
musculo-skeletal
diet & health
effect of exercise
Smoking & fitness: lung function
 Smoking cigarettes damages health & reduces fitness
 It impairs lung function by
 Reducing alveolar function
 Damaging the lining of the airways & increasing mucus
production
 Increasing the risk of lung infection, emphysema, bronchitis,
asthma, & lung cancer
 Smoking reduces vital capacity
 Smoking reduces aerobic fitness
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cardiovascular
respiratory
musculo-skeletal
diet & health
effect of exercise
Smoking & fitness: cardiac function
 Smoking cigarettes damages health & reduces fitness
 It impairs cardiac & vascular function by
 Damaging the blood supply to the heart muscle
 Damaging artery walls
 Reducing the amount of oxygen that can be carried in the blood
 Increasing the risk of angina, heart attack, & stroke
 Increasing the risk of arterial disease
 Increasing the risk of blood clots forming in the veins
Smoking reduces cardiac fitness
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cardiovascular
respiratory
musculo-skeletal
diet & health
effect of exercise
Summary
There are many benefits of regular vigorous exercise…
Reduced risk of heart & vascular diseases
Improved lung function
Strengthened bones & joints
Weight control
Relief of mental stress & better relaxation
Enhanced stamina & fitness
Better quality of life!
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