The effects of acute/
Short term exercise
on the respiratory
system
Respiratory response: increase in breathing
rate (neural and chemical control); increased
tidal volume.
Short Term - The mechanics of breathing
• When we start to exercise, such as during a
warm up the mechanics of breathing alter
considerably
• This can help to explain how we breathe in faster
and deeper during exercise, and therefore help you
to answer part of the first two questions.
• This increases the amount of air that reaches the
alveoli in the lungs.
Mechanics of breathing - Inspiration
• During exercise,
– More muscles are involved
• The sternocleidomasoid,
sclanes and pectoralis major
are now involved as well as
the diaphragm and external
intercostal muscles
– This means that the sternum
lifts further and faster than it
does at rest
– Muscles work harder
• The external intercostals
and diaphragm in particular
flattens with more force
Mechanics of breathing - Expiration
• During exercise
– Becomes an active process
• Internal intercostal muscles now
contract
– They pull the rib cage down
• More muscles are involved
– Rectus abdominus/obliques
now contract as well
• The diaphragm pushes up
harder into the thoracic cage.
Changes to lung volume
• Give an example based on a football player
that is working at maximum intensity
– Eg. He has just sprinted flat out to get on to a
through ball.
– What changes would you expect to see in the
different lung volumes from rest to this maximal
exertion.
• There is an example on the next slide that will help you
with this, and allow you to illustrate your answer
Respiratory
volumes
• Tidal Volume
– The volume of air inspired
or expired per breath
(Approx 500ml at rest)
• Inspiratory Reserve Volume
– The amount of space that is
available to draw in more air
• Eg; Breathe in normally, then
breathe in more. This extra
capacity is your IRV
• Expiratory Reserve Volume
– The amount of space that is available to breathe out, once you have exhaled
normally
• Eg: Breathe out normally, then force out more air. This is your ERV.
Respiratory
volumes
•
• Residual Volume
– Breathe out as much as
•
possible
• There is always
some air left in
your lungs
• This is your RV
(Approx 1200ml)
Vital Capacity
– Breathe in as much as you can,
and then force as much air out of
your lungs as possible.
• This is your IRV+ERV+TV,
and is your Vital Capacity
Total Lung
Capacity
– Take in as
much breath
as possible
– This is your
total lung
capacity
– ERV+IRV+TV
+RV (Approx
6000ml)
Lung volumes example
Lung Volume
Resting Volume
Change due to exercise
Tidal Volume (X)
500ml per breath
Increases up to 4 times
Frequency
12-15
Increases up to 60
Minute Ventilation (VE)
6l/min
Inspiratory reserve Volume
3000ml
Up to 175l/min in large aerobically
trained athletes
Decreases
Expiratory reserve Volume
1200ml
Decreases
Vital Capacity
4700ml
Slight decrease
Residual Volume
1200ml
Slight decrease
Total Lung capacity
5900ml
Slight decrease
Short term effects – why does our rate of
breathing get faster and deeper
• Breathing is controlled by the Respiratory
control centre
– Located in the medulla oblongata
• Split into inspiratory and expiratory centres
• Controls the respiratory
muscles that initiate breathing
• They are under
involuntary neural control
– We don’t normally
consciously control our
breathing rate
During exercise
• A number of things stimulate the
Respiratory Control Centre to work
harder
• When our muscles use Oxygen, we
produce Carbon Dioxide.
– Chemeroceptors located in the veins
• send information to the RCC
• Detect the increased content of Carbon Dioxide in the blood and the
decrease in Oxygen
– This stimulates the RCC to increase the rate and depth of breathing.
Long term effects – Vital Capacity
– After 6 weeks of training, your
respiratory muscles will become
stronger.
• This means that you will be able to use
your external intercostal muscles and
sternocleidomastoid muscles to breathe in
deeper
• And your internal intercostal muscles,
abdominals and obliques to push more air
out of the body
– This will result in an increase in
vital capacity
• Maximum amount of
air that you can
produce after you
breathe out as hard
as you can
P1/P2/M1
Assessment Ideas…
•
•
•
•
Leaflet
Information Brochure
Power Point
Spider Diagrams for each system
-Remember… If you are going for Merit: you only
explain in further detail (using examples, sports and
wider reading) the musculoskeletal, CV and
Respiratory systems.
Some added help, questions for you to
answer in your work…
• What are the acute effects of exercise on the cardiovascular
and respiratory systems
• What causes these responses? What happens during
steady state and maximal exercise
• What are the acute effects of exercise on the skeletal
and muscular systems
• What causes these responses? What happens during
steady state and maximal exercise
• What are the acute effects of exercise on the energy
systems
• What causes these responses, how do the energy
systems work together, What happens during exercise of
different intensities and maximal exercise.