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Transcript
IB
Sports,
Exercise and
Health Science
Topic 2: Exercise Physiology: Cardiovascular System
2.2.1: Composition of Blood
2.2.2: Composition of Blood - Match the statements:
Red blood cells are called…..
The main function of red blood cells
In the red blood cells haemoglobin
helps….
White blood cells protects the body…
White blood cells are also called….
White blood cells are produced…
The platelets job is to…
Platelets are smaller parts…
Plasma is 90%water and makes up…
Plasma contains plasma proteins that
help…
…erythrocytes
…is to transport oxygen
…the transportation of oxygen to the
working muscles.
… by going to the source of infection.
Leukocytes.
…in both the long bones and the
lymph tissues of the body.
…to clot the blood.
…of larger cells.
...55% of the volume of blood
…the circulation between cells and
tissues
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Topic 2: Exercise Physiology: Cardiovascular System
Section 2
Blood Flow Song: Go to the following link and write out the lyrics for the song.
http://www.youtube.com/watch?v=gIXcWE0bTwY
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Topic 2: Exercise Physiology: Cardiovascular System
2.2.3 Describe the Anatomy of the heart
Using the terms at the bottom of the page, label the diagram. Once you have finished, match each one to its
correct definition.
Aorta
Pulmonary Artery
Pulmonary Veins
Semilunar Valves
Bicuspid valve
Tricuspid valve
Left Atrium
Right Atrium
Left Ventricle
Vena Cava
Aorta
Pulmonary veins
Right Ventricle
Transports oxygenated blood from the heart to the body
Transport oxygenated blood from the lungs to the heart
Vena cava
Transport deoxygenated blood from the body to the heart
Pulmonary artery
Bicuspid valve
Tricuspid valve
Transports deoxygenated blood from the heart to the lungs
Prevent blood flowing back from the ventricles into the atria
Right atrium
Right ventricle
Pump deoxygenated blood to the lungs
Left atrium
Left ventricle
Pump oxygenated blood from the lungs to the body
Semilunar valves
Prevent blood from flowing back into the heart
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Topic 2: Exercise Physiology: Cardiovascular System
2.2.5 Outline the relationship between pulmonary and systemic circulation
Pulmonary and systemic circulation are two separate cardiovascular systems for
distributing oxygen-rich blood from the heart and lungs throughout the body. The
blood that is returned to the heart from the body via the veins has been depleted of
oxygen, or deoxygenated, and must receive oxygen again in the lungs before being
re-circulated back to the body.
Pulmonary circulation is the process by which the deoxygenated blood is pumped
from the heart to the lungs, receives oxygen there, and is pumped back into the
heart.
Systemic circulation is the process by which this oxygenated blood is pumped from
the heart and distributed via the arteries throughout the body, delivering oxygen and
other vital nutrients to the organs, muscles, and other tissues that require it.
It is then returned to the heart by the veins, where the process of pulmonary and
systemic circulation begins again.
http://www.wisegeekhealth.com/what-is-the-relationship-between-pulmonary-andsystemic-circulation.htm
Describe in detail (13 steps) a pumping cycle starting with blood, low on oxygen
coming from the upper part of the body and finishing with the oxygen rich blood
going into the aorta.
Step
1
2
3
4
5
6
7
8
9
10
11
12
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Topic 2: Exercise Physiology: Cardiovascular System
13
1. Blood- low on oxygen- flows towards the right atrium via the Vena Cava inferior and
superior.
2. The tricuspid valve opens and blood is pumped into right ventricle of your heart.
3. Right Ventricle contracts and blood passes the pulmonary valve and enters the
pulmonary artery.
4. Blood goes to your lung and becomes oxygen rich.
5. The L atrium contracts and blood goes to the L ventricle through the mitral valve.
6. The L ventricle contracts and the aortic valve opens.
7. The aortic valve quickly closes (prevent blood from going back).
8. The right atrium fills with blood and when full contracts.
9. When the R ventricle is full of blood the tricuspid valve closes (prevent blood flowing
back into R atrium).
10. The pulmonary valve closes to prevent blood from going back into R ventricle.
11. This oxygen rich blood returns from lungs through pulmonary veins and fills your L
atrium.
12. The mitral valve closes when the L ventricle is full of blood.
13. Oxygen rich blood is pumped into the aorta.
1
2
3
4
5
6
7
8
Blood- low on oxygen- flows towards the right atrium via the Vena
Cava inferior and superior
The right atrium fills with blood and when full contracts
The tricuspid valve opens and blood is pumped into right ventricle
of your heart
When the R ventricle is full of blood the tricuspid valve closes
(prevent blood flowing back into R atrium)
Right Ventricle contracts and blood passes the pulmonary valve and
enters the pulmonary artery
The pulmonary valve closes to prevent blood from going back into R
ventricle
Blood goes to your lung and becomes oxygen rich
10
This oxygen rich blood returns from lungs through pulmonary veins
and fills your L atrium
The L atrium contracts and blood goes to the L ventricle through the
mitral valve.
The mitral valve closes when the L ventricle is full of blood
11
The L ventricle contracts and the aortic valve opens
12
Oxygen rich blood is pumped into the aorta
13
The aortic valve quickly closes (prevent blood from going back)
9
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Topic 2: Exercise Physiology: Cardiovascular System
2.2.4 Describe the intrinsic and extrinsic regulation of heart rate and the
sequence of excitation of the heart muscle.
Define
Key Word
Definition
Myocyte
A myocyte (also known as a muscle cell or
muscle fiber) is the type of cell found in
muscle tissue. Myocytes are long, tubular
cells that develop from myoblasts to form
muscles in a process known as myogenesis.
There are various specialized forms of
myocytes: cardiac, skeletal, and smooth
muscle cells, with various properties. Cardiac
myocytes are responsible for generating the
electrical impulses that control the heart rate,
among other things.
Sino-atrial node
The SA node is the heart's natural
pacemaker. Stimulates atria to contract.
AV node stimulates ventricles to contract.
Acts as a bridge pathway (electrical relay
station) between the upper chambers and
lower chambers.
An action potential is a short-lasting event
in which the electrical membrane potential of
a cell rapidly rises and falls, following a
consistent trajectory.
Atrio-ventricular mode
Action Potential
Purinje fibres (Bundle of His)
Myocardial contraction
Autonomic nervous system
Purkinje fibers are specialized muscle fibers
found in the heart. Their function is to relay
impulses from the bundle to the ventricles,
causing a contraction.
Refers to the contraction of the heart muscle.
Division of the peripheral nervous system;
controls involuntary activities not under
conscious control, such as heart rate and
digestion.
The above definitions taken from wikipedia and wisegeek.
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Topic 2: Exercise Physiology: Cardiovascular System
Annotate and Explain the stages below
2.2.4 Describe the intrinsic and extrinsic regulation of heart rate and the sequence of
excitation of the heart muscle.
List the 5 steps below of intrinsic and extrinsic regulation of heart rate and the
sequence of excitation of the heart muscle. (SEE KEYNOTE)
1.
2.
3.
4.
5.
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Topic 2: Exercise Physiology: Cardiovascular System
Past Paper Question
1. How is breathing rate regulated by the body to meet the increasing
demands of exercise during a game of netball?
Answer
 Increased carbon dioxide/lactic acid/acidity.
 Detected by chemoreceptors/baroreceptors/
mechanoreceptors/proprioceptors/ thermoreceptors.
 In carotid arteries/aortic arch.
 Nerve impulses to respiratory centre/medulla.
 Nerve impulses to breathing muscles/diaphragm/intercostal
muscles.
 Deeper and faster breathing
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Topic 2: Exercise Physiology: Cardiovascular System
2.2.6 Describe the relationship between heart rate, cardiac output and stroke
volume at rest and during exercise
Cardiac Output: Define the following key terms.
Term
Definition (including formula)
Pulmonary
circulation
Part of the circulatory system that
carries blood between the heart and lungs.
Systemic
circulation
Part of the circulatory system that
carries blood between the heart and the body.
Unit
Symb
ol
l/min
Q
ml
SV
Blood pumped per minute
Cardiac output
Blood pumped per beat
Stroke volume
Individual Activity
Show your working to calculate your personal cardiac output in the space
below
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Topic 2: Exercise Physiology: Cardiovascular System
Investigation 2
Class Activity
Aim: To investigate the difference in stroke volume between males and
females.
Hypothesis
Materials
 Stopwatch
Method
1. Take your resting HR by finding your pulse and recording over 15 seconds
then multiplying by four.
2. The average Q for a person is 5 litres per minute – using this information
– calculate you stroke volume and enter the data into the data table.
3. Note down the rest of the classes results…make sure you collect
everyone’s!
4. Separate the class stroke volumes by male & female.
5. Calculate mean SV for the males and the females.
Results:
Name
Gender
Q (l/min)
5
5
5
5
5
5
5
5
HR (bpm)
SV (l)
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Topic 2: Exercise Physiology: Cardiovascular System
Analysis
1. Is there a difference between males and females? If so, explain why.
2. What conclusions can you draw about the general fitness of males
compared to females?
3. What conclusions can you draw about the general fitness of the class?
Changes to Cardiac Output during Exercise
Individual Activity – Types of Exercise
Choose the correct words from the word bank below. There are more words than required.
Sub-maximal exercise is the average method of working out; you are not working at your
physiological maximum. Heart rate is measured in beats per minute and relates to submaximal exercise in that when you are exercising, your measured heart rate is not as fast
as it could be.
When you reach your maximum amount of work that you are physiologically capable of
performing, your heart rate will plateau. Heart rate should respond in a linear fashion
to physical activity; however, other factors such as your medical history and level of fitness
may play a role. Slow exercise should increase the heart rate, but not bring it to its
maximum.
Word Bank
Maximum
increase
beats per minute
slow
fast
decrease
plateau
Linear
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Topic 2: Exercise Physiology: Cardiovascular System
2.2.6 Describe the relationship between heart rate, cardiac output and stroke
volume at rest and during exercise
Stroke Volume
Fill in the following sentences:
Stroke Volume increase during exercise- why?
Exercise places an increased demand on the cardiovascular system. Oxygen demand by the
muscles increases sharply. Metabolic processes speed up and more waste is created. More
nutrients are used and body temperature rises.
At a linear rate to the speed/ intensity of the exercise (up to about 4060% of maximal intensity).
Once 40-60% of maximum intensity is reached stroke volume reaches a
plateau.
Therefore stroke volume reaches it’s maximal during sub-maximal
exercise.
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Topic 2: Exercise Physiology: Cardiovascular System
What causes stroke volume (and therefore Q) to increase?
More blood is being returned to the heart – this is called Venous Return.
Less blood left in heart; (End Diastolic Volume- EDV; the volume of blood
in the right and/or left ventricle at end load.
Increased Ventricular Contraction (aka Diastolic Filling) occurs, this
increases the pressure and stretches the walls of the ventricles, which
means that a more forceful contraction is produced.
This is known as Starling’s Law.
(more stretch = more forceful contraction).
During maximal exercise the cardiac output will need to be increased,
however stroke volume has already reached its maximum.
Heart rate increases.
As a result of this stroke volume starts to decrease - the increase in HR
means that there is not as much time for the ventricles to fill up with
blood, so there is less to eject (causes the HR to increase even more).
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Topic 2: Exercise Physiology: Cardiovascular System
Heart Rate
Before exercise
Increases above resting HR before exercise has begun – known as
anticipatory response, is as a result of the release of adrenalin which
stimulates the SA node.
Sub-maximal Exercise
Plateaus during sub-maximal exercise, called steady state exercise, means
that the oxygen demand is being met.
Maximal Exercise
Heart Rate increases dramatically once exercise starts, continues to
increase as Stroke Volume & Cardiac Output increases to meet the oxygen
demand.
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Topic 2: Exercise Physiology: Cardiovascular System
Heart Rate decreases as exercise intensity decreases.
After Exercise
After exercise – heart rate decreases dramatically, then gradually
decreases.
Cardiac Output
Increases directly in line with intensity from resting up to maximum.
Plateaus during sub maximal exercise.
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Topic 2: Exercise Physiology: Cardiovascular System
Data Analysis of Cardiac Output
The table below shows the cardiovascular responses during dynamic wholebody exercise for 2 adult males of similar age (20 years old) and size (1.8m,
70kg). One of the individuals is sedentary and the other one is a well- trained
endurance athlete.
The data reflects 3 levels of exercise intensity:
1. Rest
2. Sub-maximal exercise (exercise at a fixed intensity)
Measurement
Intensity
Rest
-1
Sub-max.
Heart rate (beats.min )
Max.
Rest
-1
Sub-max.
Stroke volume (ml.beat )
Max.
Rest
-1
Sub-max.
Cardiac output (L.min )
Max.
Untrained adult
male 75
110
197
60
85
120
4.6
9.4
19.7
Trained adult
male 50
80
195
90
112
190
4.5
9.0
32.2
3. Maximal exercise (exercise to the point of exhaustion)
1. Evaluate the effect of training on the cardiovascular response to
sub maximal and dynamic exercise.
An untrained athlete has a higher heart rate and lower stroke volume.
Trained adult: Higher stroke volume- larger heart therefore more blood
being pushed around the body so there is more circulation’ efficiency in a
trained athlete.
2. Aside from any differences in training status, predict any
difference that you would expect if the data in the above table
were compared to an adult female.
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Topic 2: Exercise Physiology: Cardiovascular System
Females- typically smaller, smaller heart and less muscle mass. Lower
Oxygen carrying capacity. Lower aerobic capacity VO2 max.
Sub-maximal cardiovascular responses are different in children and adults.
Both boys and girls have a lower cardiac output than adults at a given
absolute sub-maximal rate of work. This lower cardiac output is attributable
to a lower stroke volume, which is partially compensated for by a higher
heart rate.
The table below shows the data from a study comparing cardiovascular
responses to cycling and treadmill running in 7-9 year old children versus
18-26 year old adults.
Exercise
Cycle 60W
Run 3 mph
Cardiac output (L.min )-1
Child
Adult
9.4
12.4
6.7
12.3
Stroke volume (ml.beat-1
Child
Adult
61.9
126.8
57.3
135.7
Heart rate (beats.min-1)
Child
Adult
153.1
97.8
11.6
92.0
1. Compare the cardiac output, stroke volume and heart rate
between the child and the adult.
Sub-maximal cardiovascular responses are different in children and adults. Both
boys and girls have a lower cardiac output than adults at a given absolute submaximal rate of work. This lower cardiac output is attributable to a lower stroke
volume, which is partially compensated for by a higher heart rate.
See page 43 SEHS course companion
2. Explain the cardiac output, stroke volume and heart rate
between the child and the adult.
Differences in sub maximal cardiovascular responses between children and
adults are related to the smaller hearts and a smaller amount of muscle doing a
given rate of work in children.
N.B.
Child has larger surface area to volume ratio than adult, (because is smaller): so child has
more heat loss per unit area, so needs a higher metabolic rate than an adult to maintain the
same body temperature.
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Topic 2: Exercise Physiology: Cardiovascular System
Child also has an additional metabolic load because it is growing,
Adaptations of the Heart to Exercise
Heart Size
Physiological Adaptation
The muscular walls of the heart increase in
thickness, particularly in the left ventricle,
providing a more powerful contraction.
Stroke Volume (SV)
Resting Heart Rate
(RHR)
The left ventricles internal dimensions increase
as a result of increased ventricular filling.
The increase in size of the heart enables the left
ventricle to stretch more and thus fill with more
blood. The increase in muscle wall thickness
also increases the contractility resulting in
increased stroke volume at rest and during
exercise, increasing blood supply to the body.
As cardiac output at rest remains constant the
increase in stroke volume is accompanied by a
corresponding decrease in heart rate.
Cardiac output increases significantly during
maximal exercise effort due to the increase in
SV. This results in greater oxygen supply, waste
Cardiac Output (Q)
removal and hence improved endurance
performance.
People with blood pressure in the ‘normal’
ranges experience little change in BP at rest or
with exercise; however hypertensive people find
that their BP’s reduce towards normal as they
Blood Pressure (BP) do more exercise. This is due to a reduction in
total peripheral resistance within the artery, and
improved condition and elasticity of the smooth
muscle in the blood vessel walls.
http://www.ptdirect.com/training-design/anatomy-and-physiology/adaptationsto-exercise/chronic-cardiovascular-adaptations-to-exercise
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Topic 2: Exercise Physiology: Cardiovascular System
Past Paper Questions
1. Explain how it is possible for a trained performer and an untrained
performer to have the same cardiac output for a given workload. (4)







Different sized hearts/hypertrophy -trained bigger;
Different stroke volumes - trained bigger;
Different heart rates - untrained higher;
Can only occur at sub maximal workloads;
At higher workloads untrained will not be able to increase their
heart rate sufficiently;
Different physiques/size/mass -untrained bigger.
2. Describe the relationship between heart rate, stroke volume and
cardiac output during rest, sub-maximal rowing and maximal rowing. (2)
 HR is the number of times the heart beats per minute
 SV is the amount of blood pumped out by the left ventricle in each
contraction.
 Q is found by multiplying the heart rate (bpm) by the stroke volume (ml of
blood/beat)
 HR increases in direct proportion to the increase in exercise intensity
 Initially Q increases as a result of both increase in HR and SV
 Maximal SV is achieved during sub-maximal work
 Any increase in Q output during maximal exercise is due solely to increase
in HR.
3. Briefly explain the terms ‘cardiac output’ and ‘stroke volume’, and the
relationship between them. (3 marks)
 Cardiac output - ‘the volume of blood pumped from heart/ ventricle in one
minute;
 Stroke volume - ‘the volume of blood pumped from the heart/ ventricle in
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Topic 2: Exercise Physiology: Cardiovascular System
one beat
 Cardiac output = stroke volume x heart rate/Q = SV x HR
Investigation 3
Calculating Maximal Heart Rate for Training
To make sure you are getting the most out of your workouts, you should
exercise within what is called your “Training Heart Rate Zone”.
This activity will teach you how to calculate for that zone/range, which is
60-80% of your maximum heart rate.
60% = low intensity, 70% = moderate intensity, 80% = high intensity
Part I- Calculate your HR Zones using both formulas
Use the Maximum HR Formula to get the HR zones:
Calculate your Resting Heart Rate (RHR)
The RHR should be taken first thing on 3 consecutive mornings upon
waking and before getting out of bed.
Calculate your estimated Maximal Heart Rate (MHR)
o (220 – Age = MHR)
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Topic 2: Exercise Physiology: Cardiovascular System
Calculate your Target Heart Rate Zone (THRZ) by multiplying by
65% and 80% of your MHR to get your ‘low’ end and ‘high’ end
threshold.
(MHR X 0.65 = 65% of MHR) and (MHR X 0.80 = 80% of MHR)
Use the Karvonen Formula to get the HR zones: (This is a much harder
way to get your zones)
Ideally, you resting heart rate will be what you are first thing in the morning
waking up.
The Karvonen heart rate method
220- (Age –Resting HR) x Intensity level + Resting HR
220 (max heart rate)
50% = Lower range of exercise intensity
85% = Upper range of exercise intensity
1. 220 – 17 = 203
2. (203 – 66) x .50) + 66 = 135 bpm – lower range
3. (203 – 66) x .85) + 66 = 182 bpm – upper range
Gives you a nice range of where you want to be with your exercise level. For
athletes they may want to go slightly higher than 85%.
Part II- Perform the following activities and write down your HR
response
Do Heart Rate Lab (one with coke)
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Topic 2: Exercise Physiology: Cardiovascular System
2.2.9 Systolic and diastolic blood pressure
Read the passage below and highlight key terms and ideas
Blood flow changes dramatically once exercise commences. At rest, only 1520% of cardiac output is directed to skeletal muscle (the majority of it goes to
the liver and the kidneys. Blood is redirected to areas where it is needed most.
This is known as shunting or accommodation. When exercising, the increased
metabolic activity increases the concentration of carbon dioxide and lactic acid
in the blood. This is detected by chemoreceptors and sympathetic nerves
stimulate the blood vessel size to change shape.
Vasodilation will then allow a greater blood flow, bringing the much needed
oxygen and flushing away the harmful waste products of metabolism. The
redistribution of blood is controlled primarily by the vasoconstriction and
vasodilation of arterioles. They react to chemical changes of the local tissue.
For example, vasodilation will occur when arterioles sense a decrease in oxygen
concentration or an increase in acidity due to higher CO2 and lactic acid
concentrations.
Sympathetic nerves also play a major role in redistributing blood from one area
of the body to another.
The smooth muscle layer (tunica media) of the blood vessels is controlled by the
sympathetic nervous system, and remains in a state of slight contraction. By
increasing sympathetic stimulation, vasoconstriction occurs and blood flow is
restricted and redistributed to areas of greater need.
When stimulation by
sympathetic nerves decreases, vasodilation is allowed which will increase blood
flow to that body part.
Define the terms systolic and diastolic blood pressure
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Topic 2: Exercise Physiology: Cardiovascular System
Function
Diastolic
Systolic
The force exerted by blood on arterial walls during ventricular
relaxation.
The force exterted by blood on arterial walls during ventricular
contraction.
Define:
Vasodilation
Vasoconstriction
Blood Pressure
Blood Vessels dilate
Blood Vessels become narrow
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Topic 2: Exercise Physiology: Cardiovascular System
Measured in blood vessels (artery)
Blood pressure is the measurement of force applied to artery walls.
Narrower vessels (vasoconstriction)
Wider vessels (vasodilation)
2.2.10
Analyse systolic and diastolic blood pressure data at rest
and during exercise
Complete the table below using the word bank below:
Describe
Explain
Skeletal muscle – massive increase in
blood flow (26 fold) to working muscle. At
maximum effort muscle takes 88% of blood
flow
Coronary vessels – blood vessels that
serve cardiac muscle (which needs oxygen
and respiratory substrates). Nearly a 5 fold
increase in blood flow during exercise.
Skin – small increase in blood flow to
the skin during exercise.
Kidneys – significant reduction in
blood flow during exercise.
Liver & gut - significant reduction in
blood flow during exercise
Brain – blood flow is maintained at
the same level during exercise
Whole body – the volume of blood
pumped per minute is the same measure as
cardiac output
The force exerted by blood on arterial walls
during ventricular relaxation.
As a working muscle, the heart needs its
share of oxygen. When the heart rate
increases, it needs more oxygen to make
energy and to remove CO2.
Temperature regulation. Vasodilation of
arterioles increases flow rate to the skin. We
go red and lose some heat through
evaporation of sweat.
Non-essential function during exercise.
Non-essential function during exercise.
The brain needs a constant supply of oxygen
to function properly. Exercise makes no
change to this demand.
Increased cardiac output is a response to
increased work rate and the associated
demand for energy. Cardiac output is raised
by increasing heart rate and stroke volume.
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2.2.11
Topic 2: Exercise Physiology: Cardiovascular System
How does Systolic and diastolic blood pressure respond to
dynamic and static exercise.
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Topic 2: Exercise Physiology: Cardiovascular System
Complete the paragraphs below using terms for the word bank provided
The heart muscle contracts in two stages to squeeze blood out of the heart.
This is known as systole.



In the first stage, the upper chambers (atria) contract at the same time,
pushing blood down into the lower chambers (ventricles).
Blood is pumped from the right atrium down into the right ventricle and
from the left atrium down into the left ventricle.
In the second stage, the lower chambers contract to push this blood out
of the heart to either the body via your main artery (aorta) or to the lungs
to pick up oxygen.
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Topic 2: Exercise Physiology: Cardiovascular System
The heart then relaxes – known as diastole. Blood fills up the heart again, and
the whole process, which takes a fraction of a second, is repeated.
(i)
Blood pressure is the measurement of force applied to artery walls. It
increases during exercise because more blood is pumped around the
body, increasing pressure in the blood vessels.
(ii)
Systolic: The blood pressure when the heart is contracting. It is specifically
the maximum arterial pressure during contraction of the left ventricle of
the heart. The time at which ventricular contraction occurs is called
systole.
In a blood pressure reading, the systolic pressure is typically the first
number recorded. For example, with a blood pressure of 120/80 ("120
over 80"), the systolic pressure is 120. By "120" is meant 120 mm Hg
(millimeters of mercury).
(iii)
The diastolic pressure is specifically the minimum arterial pressure during
relaxation and dilatation of the ventricles of the heart when the ventricles
fill with blood.
In a blood pressure reading, the diastolic pressure is typically the second
number recorded. For example, with a blood pressure of 120/80 ("120
over 80"), the diastolic pressure is 80. By "80" is meant 80 mm Hg
(millimeters of mercury).
Right atrium
Artery
Lower chambers
Systole
Upper chambers
Left ventricle
Oxygen
Blood vessels
Diastole
Systolic
measurement of force
contracting
ventricular
Diastolic
Ventricles
Second
first
2.2.11: Data analysis questions
Activity
Rest
Diastolic pressure
(mmHg) 75
Systolic Pressure
(mmHg) 11
6
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Topic 2: Exercise Physiology: Cardiovascular System
80kg healthy
male
100 kg
unhealthy male
Running
Lifting
80
150
Rest
95
18
0
24
0
15
The table above presents data for a healthy trained 80kg male at rest and
performing two different actions (running fast, a dynamic activity, trying to lift
a very heavy object, static but very high forces), as well as resting data for
another untrained and unhealthy individual.
Answer the following questions
1. Compare the effect of dynamic exercise and static exercise on blood
pressure? See keynote
Answer
2. Explain why one is higher than the other? See keynote
Answer
3. Describe the difference between the two participants at rest.
Answer
Effects of Exercise
As you begin to exercise, your body produces more carbon dioxide, which causes you to breathe
more quickly. Your heart responds by pumping harder to produce more oxygen. Next, your blood
pressure increases and your arteries widen, which brings more blood to your heart. This action
causes the heart to beat even more. An unfit person has a higher heart rate than a fit person
because his body works harder during this process. Often, the arteries are clogged and the blood
pressure is high, forcing the heart to beat faster than normal.
http://www.livestrong.com/article/370950-what-is-an-unfit-persons-heart-rate-while-exercising/
2.2.12: Redistribution of blood during exercise
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Topic 2: Exercise Physiology: Cardiovascular System
Factors affecting blood pressure
Factor
Cardiovascular centre
Smoking
Diet
Adrenaline
Increase in blood viscosity
2.2.12
Explanation
Diameter of blood vessels controlled
by stimulation of sympathetic and
parasympathetic nerves.
Nicotine causes vasoconstriction
Build up of fatty deposits in vessels
High fat diet leads to build up of fatty
deposits in blood vessels
Causes selective vasoconstriction &
vasodilation
Excess water loss (sweating/excessive
urination)
Compare the distribution of blood at rest and during exercise
Compare the values.
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Topic 2: Exercise Physiology: Cardiovascular System
2.2.8: Cardiovascular Drift
We used to think that exercising at a steady level led to the body
reaching a steady state, where the heart rate remained the same.
However, research has shown that it does not stay the same but instead
increases slowly. This is Cardiovascular drift.
It is characterized by a progressive decrease in stroke volume and
arterial blood pressure, together with a progressive rise in heart
rate.
It generally occurs during prolonged exercise in a warm
environment despite the intensity of the exercise remaining the
same.
It is suggested that cardiovascular drift occurs because when we
sweat a portion of the lost fluid volume comes from the plasma
volume.
The decrease in plasma volume reduces venous return and stroke
volume.An increase of body temperature results in a lower venous return
to the heart, a small decrease in blood volume from sweating.
A reduction in stroke volume causes the heart rate to increase to
maintain cardiac output. If CVD did not occur, a person would
have to lower his/her intensity.
Katch, McArdle, Katch (2011)
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Topic 2: Exercise Physiology: Cardiovascular System
In summary: Explanation for Cardiac Drift
Continuous exercise – decrease in volume of blood plasma.
Fluid seeps into surrounding tissues and cells
Fluid lost to sweating
If athletes fail to re-hydrate, can further reduce the volume of blood
returning to heart
Reduces blood volume and hence reduces stroke volume.
Therefore reduced venous return to the heart.
…..According to Starling’s Law
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Cardiac output (Q) needs to be kept constant
Q = SV x HR - if SV decreases, then HR must increase.
Hence there is a need for increase in heart rate during steady state
exercise to maintain redistribution of blood flow.
2.2.13 Describe the cardiovascular adaptations resulting from aerobic
training
Please read and highlight the following, which you think is important.
2.2.13 Cardiovascular adaptations resulting from endurance exercises
Acute cardiovascular (circulatory system) responses to exercise
1. When you begin to exercise, your HR increases to
to the
working muscles. If you exercise at a constant pace, your HR will level off &
remain constant until you go faster or stop. This is ‘steady state’, and
indicates that the muscles are receiving enough blood & O2 to keep working
at that pace. (O2 supply = O2 demand).
2. Stroke volume is the amount of blood pumped out of the L ventricle with
each heart beat (contraction). Your SV depends on the size of your left
ventricle, which is determined by a combination of genetics & training. When
you begin to exercise, your heart muscle contracts more forcefully to increase blood (& hence O2 ) supply to your muscles. This causes a more
complete emptying of your ventricles, so SV increases.
3. Cardiac Output is the amount of blood pumped out of the heart’s left
ventricle in 1 minute.
4. CO = SV x HR
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Topic 2: Exercise Physiology: Cardiovascular System
When you exercise, your Cardiac Output increases in an effort to increase the
blood supply (& hence O2 delivery) to the working muscles.
5. Blood Pressure is a measure of the pressure produced by the blood being
pumped into the arteries.
Systolic B.P. - pressure as the LV ejects the blood into the aorta during heart
contraction.
Diastolic B.P. - pressure in the arteries during relaxation of the heart.
Blood Pressure increase’s during exercise because SV, HR & CO all increase,
more blood is pumped into the arteries more quickly.
Blood Pressure is the measurement of force applied to artery walls.
During exercise, blood flow to the working muscles increases because of increased Cardiac Output & a greater distribution of blood away from nonworking areas to active muscles. 80-85% of Cardiac Output goes to working
muscles, because muscle capillaries dilate to allow more blood flow to the
muscles called vasodilation. Blood flow to kidneys, stomach & intestines ¯
decreases because the capillaries constrict - called vasoconstriction.
Blood flow to the lungs increases, as the right ventricle increases its activity
during exercise. To allow for this increased blood flow to the muscles, there
must be an accompanying increase in venous return (blood flow back to heart
through the veins).
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Topic 2: Exercise Physiology: Cardiovascular System
Due to an increase in sweating, the blood plasma volume decreases during
strenuous exercise, especially in hot weather.
Acute Muscular Responses to Exercise

contraction rate

recruitment of muscle fibres & motor units to produce more force

muscle temperature
 Depletion of fuel stores used to produce energy for contractions

blood flow to muscles (blood vessels dilate)

O2 attraction at the muscle
During exercise & recovery, more O2 must be delivered from the lungs to the
working muscles, & excess O2 must be removed from the working muscles.
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Topic 2: Exercise Physiology: Cardiovascular System
Acute respiratory responses to exercise
During exercise & recovery, more O2 must be delivered from the lungs to the
working muscles, & excess O2 must be removed from the working muscles.
 respiratory rate

tidal volume

ventilation
 
lung diffusion
 
O2 uptake, or volume of O2 consumed



Respiratory rate
At rest, you breathe about 12-15 times each minute. When you begin to
exercise, the CO2 level in the blood ’s, because CO2 is a waste product of
energy production. This triggers the respiratory centre in your brain & you
breathe faster.

tidal volume- is the size of each breath taken and during heavy
exercise, tidal volume can increase to 2.5L per breath as the body tried to
increase the oxygen supply to the blood.

ventilation- the amount of air breathed in 1 minute dependent on the
number of breaths and the size of each breath.

lung diffusion- increase in in O2 diffucion from the alveoli to the
blood because of a massive increase in blood flow to the lungs and
dilation of the capillaries surrounding the alveoli.

O2 uptake, or volume of O2 consumed- When you begin to exercise,
your VO2 increase’s as your body absorbs more O2 & uses it to produce
more aerobic energy.
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Topic 2: Exercise Physiology: Cardiovascular System
Chronic Training Adaptations
When we discuss chronic adaptations to training, we are assuming that
training has been occurring for a minimum of 6-8 weeks, training at least
3 sessions per week.
2.2.14 Explain maximal oxygen consumption.
VO2max
Maximum oxygen consumption, also referred to as VO2max. Fitness can be
measured by the volume of oxygen you can consume while exercising at
your maximum capacity. Maximal Oxygen Consumption is sometimes referred
to as maximal aerobic power or aerobic capacity. Those who are ‘fitter’
have higher VO2 max values and can exercise more intensely than those who
are not as well conditioned.
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Topic 2: Exercise Physiology: Cardiovascular System
2.2.14: Definition - VO2 Max
IB:
VO2 max is the maximum amount of oxygen in milliliters that
an individual can utilize whilst performing dynamic exercise.
Q1. Why is VO2 expressed as mL kg-1 per minutes?
Answer
 VO2 max is directly related to body mass;
 Expressing relative to body mass allows comparison of individual
of different sizes
Q2: State the different factors that affect VO2 max/aerobic
capacity?
Answer










Specific exercise
Level of/type of fitness/RBC count/health/social habits
Whole body movements
Training Zones
Altitude training
Age
Gender/Sex
Asthma
Body composition/Body fat
Blood doping (illegal and dangerous)
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Topic 2: Exercise Physiology: Cardiovascular System
Read Below
Training can have the effect of making the CVR system more efficient and
improving your Vo2 max scores. The effects depend on the type of training,
its intensity and its duration. Recent research suggests that you can
increase your VO2 max by working out at an intensity that raises your
heart rate to between 65 and 85% of its maximum for at least 20
minutes three to five times a week. Interval training has also been
indentified as an effective training method (high intensity + rest periods) with
your HR recovering to at least 120bpm.
Effects can include improved or increased ability:
o to metabolise fat
o of the blood to ‘pick up’ and
transport oxygen from the
lungs
o of the muscles to use oxygen
o to remove waste products
o to increase VO2 max
o to work at a higher
percentage of VO2 max
o to recover, both during and
after exercise
o to regulate body temperature
o to work faster/harder for
longer
o to reduce risk of coronary
heart disease/diabetes/health
disorders.
Past Exam Q: How can specific training increase an athlete’s VO2
Max?
o Improve the efficiency of the CV system
o Hypertrophy of the heart = greater quantity of oxygenated blood pumped
per beat
o Marginal increases in surface area of the alveoli/lung capacity
o Increased pulmonary diffusion
o Improve the ability of the muscles used to utilize oxygen
o More myoglobin and more and bigger mitochondria in the muscles
o Increased rate of diffusion at the tissue
o Increased quantity of haemoglobin in the blood
o Improve the efficiency of the muscles used to generate energy
o Increased vascularisation of the heart/muscles (the development of blood
vessels)
o
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2.2.15
Topic 2: Exercise Physiology: Cardiovascular System
Discuss the variability of maximal oxygen consumption in selected groups
Question: List the factors that VO2 max depends on.
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Topic 2: Exercise Physiology: Cardiovascular System
Factor
Heredity
Age
Sex
Body size and
composition
Explanation
Genetic effect is currently estimated at approximately 20-30% for
VO2 max, 50% for maximum heart rate, and 70% for physical
working capacity.
Absolute values for girls and boys are similar until age 12. At age 14 VO2
max value for boys 25%> and by age 16, the difference exceeds 50%.
After age 25 its all down-hill (VO2 max declines at a rate of 1% per year
after age 25). BUT one’s habitual level of physical activity has far more
influence on aerobic capacity than age!
Even among trained endurance athletes, the sex difference for VO max
= 15-20% mainly due to differences in:
(1) Body Composition and (2) Haemoglobin.
An estimated 69% of the differences in VO2 max scores among
individuals can be explained by variations in body mass.
Mode of exercise
Highest values are generally found during treadmill exercise, lowest on
bicycle ergometer test; specificity is very important.
Muscle fiber type
Slow oxidative fibers - highest oxygen consumption.
Altitude
Low partial pressure of O2 in the atmosphere. Lower partial pressure of
O2 in the arterial blood. Lower haemoglobin saturation
Higher temperature - higher oxygen consumption.
Temperature
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2.2.15:
Topic 2: Exercise Physiology: Cardiovascular System
Discuss the variability (data) of maximal oxygen consumption (Vo2)
in the different groups above (6)
 Untrained v Trained
 Young v Old
 Male v female
You will need to also look at (1) heart rate levels, (2) SV output, and
(3) cardiac output to gain extra discussion points and apply to the
above groups (2.2.7)
Mean value of VO2 max
Non - trained
Endurance
Trained
*Male (46- 55 Yr
old)
*Female (46-55 Yr
old)
Male (40- 49 Yr
old)
Female (40-49 Yr
old)
*Male (36-45 Yr
old)
*Female (36-45 Yr
old)
Male (40 Yr old)
Female (40 Yr old)
25-28 mls/kg/min
20-24 mls/kg/min
38-40 mls/kg/min
31-32 mls/kg/min
51 mls/kg/min
45 mls/kg/min
3.5 litres/minute
(3,500ml)
2.7 litres/minute
(2,700ml)
Endurance
Cyclist/Runners
-
75 mls/kg/min
42-46 mls/kg/min
Young Person
*Male (18-25 Yr
old)
*Female (18-25 Yr
old)
Male (20-29 Yr old)
Female (20-29 Yr
old)
38-44 mls/kg/min
42-49 mls/kg/min
35-37 mls/kg/min
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Topic 2: Exercise Physiology: Cardiovascular System
Professional Footballers
Elite Footballers
2.2.16:
50 mls/kg/min
60 mls/kg/min
Outline the different tests/modes of exercise which can test
Maximum oxygen consumption (VO2max )?
Key point is that data generated from the different tests/exercise is reflected
by the quantity of activated muscle mass.
Answer






Multistage fitness test
Gas analysis Test
Treadmill Test
Bench Step Test
Bicycle Test
Arm crank exercise (cycling arms, similar to bike pedaling)
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Topic 2: Exercise Physiology: Cardiovascular System
Investigation 2
Practical Activity – Bleep Test
(http://www.topendsports.com/testing/beepcalc.htm)
What is tested: VO2 max- aerobic fitness level
Equipment needed: Stereo; bleep test CD; cones
Purpose of test: To estimate maximal oxygen uptake and utilization (VO2)
by administering a progressive shuttle run test.
Procedure & Measurement
1. Measure a distance of 20 metres and mark with two cones.
2. The client should perform a short warm including CV and stretching.
3. Start the CD, the participants will run 20 metres to the furthest cone when the first three
bleeps sound.
4. When the bleep sounds on the CD the participant turns around to run back.
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Topic 2: Exercise Physiology: Cardiovascular System
5. The client must reach the line before the third bleep
6. The participants continue to run between the cones and the time between the bleeps
becomes shorter- hence the participants need to run faster to reach the cones.
7. If the participant fails to get to the other end before the bleep on 3 consecutive occasions
then they are out.(2 chances).
8. Record the level at which the participant stopped the test.
9. Compare to VO2 max tables.
Notes: As this is a maximal test, certain precautions should be taken. Participants should
have no apparent health problems.
Stage
Level
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
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Topic 2: Exercise Physiology: Cardiovascular System
* * mark off the stage you reached, for each level, the last box filled in is your score**
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