The
Physiology of
Fitness
Acute/ Short term effects of
exercise
Task…
In 4 equal groups, each group will be assigned a system to research.
You need to make sure your group researches your particular area
thoroughly and covers the following responses depending on what
system has been assigned. Your group will then present back the
findings to the rest of the group through a detailed and informative A3
poster.
• Musculoskeletal response: increased blood supply; increase in
muscle pliability; increased range of movement; muscle fibre micro
tears
• Energy systems: phosphocreatine; lactic acid; aerobic; energy
continuum; energy requirements of different sport and exercise
activities
• Cardiovascular response: heart rate anticipatory response; activity
response; increased blood pressure; vasoconstriction; vasodilation
• Respiratory response: increase in breathing rate (neural and
chemical control); increased tidal volume.
Musculoskeletal system
The short
term effects
on MUSCLES/
JOINTS and
BONES
Musculoskeletal response: increased blood
supply; increase in muscle pliability; increased
range of movement; muscle fibre micro tears
Short term effects of & responses to
exercise – Bones & Joints.
• We produce more synovial fluid
– Movement stimulates the secretion of synovial
fluid.
• The joints become warmer
– Exercise increases the bodies temperature
– The synovial fluid becomes thinner, making
movement more efficient.
• The range of movement increases
– Due to the fact that the synovial fluid is thinner
and warmer
• All of this is because exercise makes our joints
move quickly, so there needs to be more
synovial fluid in the joints to allow and assist this
movement
When we start to warm up:
• The muscles need energy in the form of
glycogen to make the sarcomeres contract.
– So the heart (cardiac muscle) beats faster to
provide the glycogen to the muscles via the
blood.
• The conversion of chemical energy (from the
Glycogen) to movement (contraction of the
sarcomeres) causes a waste product – HEAT.
– The muscle become warmer.
• This also allows them to operate more efficiently, up
to a point.
• Once this point is reached, we need to get rid of
heat, hence why we go red and get hot. – Our body
is trying to remove the heat
In a warm up…
• We are working quite lightly
(aerobically)
– This means that the muscles are
demanding Oxygen to continue
contracting at that low intensity.
– The nervous system detects this an
makes the heart pump faster
• Because our muscles are demanding
more Oxygen we also begin to take
up more Oxygen from the blood as it
passes through the muscles
– The capillaries become more dilated
allowing this to happen
Within the Muscles
• More fibres are involved
in contraction
– This means that the
contractions are stronger
• Because more muscle
fibres are contracting,
they have less
opportunity to rest, so
there is more muscular
contraction.
Damage to the muscles
• In the short term,
muscles are damaged by
exercise (microtears)
– This is why we feel sore
after exercise
– Only with appropriate rest
and food, can we recover
• In fact we should recover
stronger than before the
exercise.
•
•
Different types of muscles
Each of the muscles reacts differently to
exercise
Skeletal
– Demands Oxygen and Glycogen
•
•
•
At rest 20% of our blood goes to our
muscles.
In a warm up 50% of our blood goes to our
working muscles
In intense exercise 80% of our blood goes
to our working muscles
– Works harder
– Warms up
• Cardiac
– Works harder (beats more often and with larger amount of
blood in each beat) to provide the Oxygen and Nutrients to
the skeletal muscle via the blood, and get rid of the Waste
products of exercise (Carbon Dioxide, Water and Heat).
• Involuntary
Blood is shunted away from the parts of the body that don’t need it
Eg the stomach gets 25% of our blood during rest. This can reduce
P1/P2/M1