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• acute responses to exercise• acute responses to exercise• acute responses to exercise• acute responses to exercise• acute responses to exercise
Physiological Requirements of Physical ActivityPhysiological Requirements of Physical ActivityPhysiological Requirements of Physical ActivityPhysiological Requirements of Physical ActivityPhysiological Requirements of Physical Activity
Data Analysis - Heart Rate Responses to Exercise 11
Laboratory Activity - Acute Responses to Exercise 12
Data Analysis - Blood Lactate Accumulation 14
Practical Activity - Acute Responses to Exercise 15
Practical Activity - Oxygen Uptake in Response to Exercise 17
Test 19
Test Answers 23
Overhead Masters 18
EDUGUIDE - PO BOX 2340 NORTH RINGWOOD VIC 3134 • 0416116952
The Masters are intended as an aid to teachers and are not a definitive course outline or summary. They represent the authors’ interpretation andapproach and are not endorsed by any governing body. They provide the individual teacher with the opportunity to mould them to suit theircircumstances and thereby satisfy themselves that they have adequately met the requirements of their courses.
Any similarities to existing worksheets are coincidental.
Acknowledgements - Graphics generated by:- • New Horizons Computer Service Collection 1993• Art Explosion, Nova Development Corporation, 1996
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At the onset of exercise acute responses which depend on a number of factors including intensity, duration, number andtype of muscles used, lead to an increase in oxygen uptake. Oxygen intake continues to rise in response to exerciseintensity until maximum levels (V0
2 max ) is reached.
1. Pulmonary ventilation rises at the onset of exercise as more air moves in and out of the lungs. Ventilation iscomposed of two phases known as inspiration and expiration and determines the level of oxygen intake.
a. Define minute ventilation
b. How is minute ventilation determined?
c. Describe what happens to ventilation:-i. before onset of exerciseii. during exercise - immediate
- prolongediii. recovery - immediate
- prolonged
2. The amount of oxygen transported to muscles is dependant on how much diffuses from the lungs, theconcentration of oxygen in the blood, and volume of blood being delivered to the working muscles.
a. Discuss how the following factors influence the diffusion of oxygen into the blood:-• surface area of lungs• alveolar capillary density• red blood cell and haemoglobin concentration
b. The volume of blood being delivered to working muscles is determined by cardiac output.i. Define cardiac output.ii. Discuss what happens to cardiac output at the onset of exercise.iii. Describe the relationship which exists between cardiac output and oxygen consumption from rest
to maximal exercise.
c. Discuss how vasodilation and vasoconstriction of blood vessels redistributes blood flow to workingmuscles.
3. Arteriovenous difference reflects how much oxygen is extracted by muscle tissue.Discuss the role of myoglobin in the uptake of oxygen by muscle cells.
4. Oxygen is utilised in the muscle cells to replenish ATP via the aerobic energy pathways.How do the size and number of mitochondria in muscle cells influence the level of oxygen consumption?
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The diagram below shows the oxygen consumption during submaximal exercise.
1. Explain why oxygen uptake rises at the onset of exercise.
2. Identify the relationship between oxygen uptake and exercise intensity.
3. Describe the acute responses which enable:-i. the respiratory system to take in oxygenii. the cardiovascular system to transport oxygeniii. the skeletal system to take in and utilise oxygen
4. a. Define 02 deficit.
b. Explain why 02 deficit occurs at the onset of exercise.
c. The shortfall in oxygen supply in 02 deficit means that the body must provide energy from anaerobic
pathways to meet the demands of a high intensity activity.Which energy system/s provide energy to meet this shortfall?
d. Refer to figure 1.Would you expect this athlete to exhaust their anaerobic energy sources whilst in 0
2 deficit.? Why?
5. a. Define steady state.b. In steady state a number of the immediate responses to exercise remain until exercise stops and the
recovery process can begin.Discuss how exercising in steady state will influence the following acute responses to exercise:-i. depletion of creatine phosphate storesii. accumulation of blood lactateiii. increase in muscle temperatureiv. depletion of glycogen stores
0 2 C
onsu
mpt
ion
02 Consumption - Rest
Figure 1
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6. The graph below indicates the redistribution of cardiac output during exercise.
a. Identify the organs to which blood flow:-i. increases at the onset of exerciseii. decreases at the onset of exercise
b. Describe the process which enables this redistribution of blood flow to occur.
c. Explain why it is necessary to redirect cardiac output during exercise.
6. a. Define 02 debt.
b. Would you expect the athlete in figure 1 to have a large 02 debt? Why?
7. In recent studies another term to describe the oxygen consumption in recovery has been used - Excess PostOxygen Consumption (EPOC).a. Describe how the excess oxygen consumed in the fast phase is utilised in relation to high energy phosphate
stores, myoglobin and haemoglobin.
b. Discuss what happens to blood lactate in the slow phase of EPOC.
c. Explain the influence an elevated core temperature and high levels of hormone secretion (catecholamine)has on metabolism and oxygen consumption.
Distribution of Blood Flow
0
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70
80
90
100
Rest 10 20 40 60 80 100
Exercise Intensity (% of max)
Blo
od F
low
(% o
f car
diac
out
put)
Distribution of Blood Flow
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Maximum oxygen uptake is used as the most accurate measure of a person’s cardiorespiratory fitness or aerobic power.It is a measure of our ability to; pump blood, ventilate large volumes of air, transport oxygen in the blood and use oxygenat muscular sites to produce energy. The most accurate measure of an individuals V0
2 max are conducted in the labora-
tory although a number of field tests have been developed to predict V02 max levels.
Aim:Aim:Aim:Aim:Aim:
To assess the V02 max levels of individuals through a sub-maximal test.
Coopers Twelve Minute RunMeasure a course placing cones at 10m intervals. Each subject runs as far as they can in the allocated time.Record:-• distance covered (metres)• V0
1. The test is based on the assumption that the subject who runs the greatest distance in the allocated time has alarger V0
2 max.
(i) Which energy system and related fitness component is being assessed in this test?(ii) Discuss the characteristics of this system which make it suited to prolonged sub-maximal activities.
2. At the commencement of the test when the subject is in oxygen deficit, which energy system is usedpredominantly?
3. Often in the concluding phases of the test, subjects begin to sprint. Under these circumstances which is the majorenergy system utilised?
4. Maximal oxygen uptake is influenced by a number of physiological factors such as haemoglobin levels, cardiacoutput, muscle fibre types, mitochondrial densities and arteriovenous differences.(i) Compare the scores of each subject with those in table 1.2 and 1.3.(ii) Discuss how the development of these physiological characteristics could influence an individual’s ability to
deliver oxygen to the working muscles. Refer to development of specific characteristics related to subjectsactivity levels.
5. Tests of college athletes reveal that the average V02 max for 17-18 year old females is 40 ml/kg/min compared to a
average V02 max of 50 ml/kg/min for 17-18 year old males.
Compare the scores for males and females in your group.(i) Do your scores follow this trend?(ii) Discuss the factors which may account for the difference in V0
Describe the role oxygen plays in the production of energy for working muscles.
V0 max for selected athletes
Table 1.2
Table 1.3
2 Athletes V0
2 Max
(Females) (ml/kg/min)
• 16-25 sedentary 35
• 16-25 active 45
• Hockey player (elite) 50
• State grade squash 52
• Middle distance runner
(elite) 62
Athletes V02 Max
(Males) (ml/kg/min)
• 16-25 sedentary 47
• 16-25 active 51
• AFL Footballers 54
• NBL Basketballers 54.5
• State grade squash player 60
• Hockey player (elite) 61
• Middle distance runner (elite) 67
• Long course triathlete 80
• Marathon runners 74
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The percentage contribution of fuels in energy production is determined by factors such as exercise intensity, oxygendelivery and fitness levels of individuals.
The graph below indicates the percentage contribution of energy stores during a marathon race which took 3 hours 40min. to complete.
Start - 2 hours
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80
90
Carbohydrates Fats
Fuel
Series1
2hr 11min - 3hr 40min
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60
70
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90
100
Carbohydrates Fats
Fuel
Series1
1. Discuss why carbohydrates contribute more to energy production in the first two hours of the run.
2. What role does oxygen play in the metabolism of glycogen to provide energy for workingmuscles?
3. Why does the athlete use a higher percentage of fats after 2hrs 10min? Discuss what occurs to the demand foroxygen and the intensity of the workload once the runner begins to rely on fats as a fuel source.
An elite marathon runner on a training run uses the following percentage of fuel stores.
4. Explain why the elite athlete is able to use a higher percentage of fats at the start of the training run.
5. Discuss what factors may contribute to the runner consuming a higher percentage of carbohydrates towards theend of the training run. What advantages does the athlete have in sparing glycogen stores?
Start - 1.20
0
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70
Carbohydrates Fats
Fuel
Series1
1hr 21min - 2hr 40min
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90
Carbohydrates Fats
Fuel
Series1
1hr 21min - 2hr 40min
Carbohydrates Fats
Fuel
Per
cent
age
cont
ribut
ion
Start - 1hr 20min
Carbohydrates Fats
Fuel
Per
cent
age
cont
ribut
ion
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energy & O energy & O energy & O energy & O energy & O����� delivery delivery delivery delivery delivery
The following graphs indicate the stroke volume, heart rate and cardiac output during exercise of trained and untrainedindividuals.
Maxim
um
s
Maxim
um
s
Maxim
um
s
Maxim
um
s
Str
oke
Volu
me
(ml/b
eat)
Hea
rt R
ate
(bpm
)
Time (mins)
Stroke Volume
Heart Rate
Time (mins)
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responses to exercise responses to exercise responses to exercise responses to exercise responses to exercise
.....
1. Use the data in the graphs to identify the acute changes which take place to stroke volume, heart rate and cardiacoutput during exercise.
2. Discuss why changes in stroke volume, heart rate and cardiac output are needed during exercise.
3. Describe the physiological characteristics of the trained athlete’s heart which account for the higher strokevolume.
4. Discuss the relationship between resting heart rate and stroke volume for the trained and untrained subjects.
5. Explain why the heart rate response to exercise is lower for the trained athlete than the untrained subject duringsub-maximal exercise.
6. Why does the trained athlete have a lower cardiac output at sub-maximal levels than the untrained individual?
7. Which subject has the largest cardiac output? Refer to specific values. Why is it possible for this subject to recorda large cardiac output during exercise?
8. Summarise the long term effects endurance training has on stroke volume, heart rate and cardiac output.
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Heart Response
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20
40
60
80
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120
140
160
180
200
Rest 5 10 15 20 25
Time (mins)
Hea
rt R
ate
(bpm
)
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heart rate response to exercise heart rate response to exercise heart rate response to exercise heart rate response to exercise heart rate response to exercise
The graph below indicates the heart rate response of two runners during a 5.24k run completed in 25:37 at an averagepace of 4:53 min/km.
Acknowledge the assistance of Nic Cooper andLucy Bowman of Eltham High in the collection of data.
1. a. What is the resting heart rate of:-• subject A• subject B
b. Given the subjects are approximately the same body weight discuss factors that could contribute thedifferences in resting heart rate.
2. With reference to specific data compare the heart rate responses of each subject to the run.
3. Discuss how differences in the following acute responses to exercise could account the observed heat rateresponses:-
• ventilation• diffusion of gases• cardiac output• venous return• oxygen consumption and ateriovenous difference
4. a. Which subject would be closer to their lactate inflection point during the run? Outline reasons for yourchoice.
b. Explain what would happen if the athlete went past their lactate inflection point.
5. Which subject would be running closer to their steady state? Outline reasons for your choice.
Subject A
Subject B
//////////
Introduction:Introduction:Introduction:Introduction:Introduction:Heart rate increases in response to exercise and will level off during a submaximal exercise bout. The level at which theheart rate stabilises is dependant on the fitness of the individual.
Aim:Aim:Aim:Aim:Aim:To record and compare the heart responses to submaximal exercise.
Equipment:Exercise bikesStopwatches
Procedure:Procedure:Procedure:Procedure:Procedure:1. Record resting heart rate (bpm)
2. Commence pedalling at cadence of 100rpm (or equivalent workload).
3. Continue pedalling for 6 minutes recording heart rate at 1 minute intervals.
4. Reduce the workload for a 3minute cool-down recording the heart rate at 1 minute intervals.
5. Observe and record physical changes that occur to subjects during activity (e.g colour / perspiration rates)
2. Describe the heart rate response during the activity.
3. Explain why heart rate increases at the onset of exercise.
4. a. Did heart rate level off during the activity? Explain why it either levelled off or continued to rise.b. What is the term given to this state where heart rate remains the same?c. Discuss factors that contribute to the levelling off of heart rate during exercise.
5. a. How would you expect stroke volume to respond during the activity?b. Do you think the changes in stroke volume would be similar for each subject? Discuss.
6. a. What happens to cardiac output at the onset of exercise?b. What percentage of cardiac output would you expect to be directed to the working muscles during this
activity?c. Describe the processes within the body that enable blood flow to be redirected.
7. The graph below shows the concentration of oxygen in arterial and venous blood.
8. a. Which line would represent:-- arterial blood- venous blood (exercise)- venous blood rest
b. Explain the changes that occur to ateriovenous difference during exercise.
9. a. Describe the physical changes that were observed as the subjects completed the activity.b. Why do these changes occur and how do they contribute to the regulation of core body temperature.
Conclusion:Conclusion:Conclusion:Conclusion:Conclusion:Draw a graph to indicate the heart rate response of a fit individual performing a constant submaximal exercise such asthe one completed in this lab. Use appropriate heart rate values.
Oxygen Concentration of Arterial and Venous Blood
0
5
10
15
20
25
Rest 1 2 3 4 5 6 7 8 9
Arterial blood
Venous blood
Venous blood
mL
/ 100
mL
Minutes
A
A
C
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Blood Lactate Levels as Running Speed Increases
0
1
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4 5.5 7 8.5 10 12 13 14 16 17
Running speed (km/h)
Blo
od
lact
ate
(m
mo
l/L)
The graph below shows the blood lactate concentration as running speed increases.
1. Outline the process during exercise that results in the production of lactate.
2. a. Up until which running speed do blood lactate levels remain relatively constant?b. Describe the metabolic fate of lactate during this phase of the activity and how this contributes to
maintaining a relative constant level of blood lactate.
3. a. Define lactate inflection point.b. At which running speed does the athlete exceed lactate inflection point?c. Explain why blood lactate levels increase past lactate inflection point.
4. a. Would you expect athletes to exceed lactate inflection point at the same running speed?Justify your choice.
b. Which type of training would you undertake to delay the point at which you exceed lactate inflection point.
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data analysis data analysis data analysis data analysis data analysis
blood lactate accumulationblood lactate accumulationblood lactate accumulationblood lactate accumulationblood lactate accumulation during exercise during exercise during exercise during exercise during exercise
/"/"/"/"/"
TASK: Participate in a moderate to vigorous aerobic activity for a period of 15 - 20 minutes and record thephysical changes you observe.
Changes Observed Straight after run 5 mins after run
• strong / rapid / regular • slower
• weak / rapid / regular • faster
• strong / rapid / irregular • no change
• weak / rapid / irregular
• no change
• gasping • slower
• panting • faster
• comfortable • not as deep
• no change • no change
• bright red • still red
• red • still pale
• pink • still pink
• pale • normal
• no change
• dripping • dripping
• beading sweat • beading sweat
• clammy • clammy
• no change • no sweating
• no change
Heart
Breathing
Perspiration
Colour
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oxygen uptake in response to oxygen uptake in response to oxygen uptake in response to oxygen uptake in response to oxygen uptake in response to exercise exercise exercise exercise exercise
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4. a. Define “steady state”. __________________________________________________________________
1. Subject A has a V02 max of 52ml/kg/min and subject B recorded a V0
2 max of 44 ml/kg/min.
a. Label on the graph the heart rate response which you would expect from subject A.
b. Which subject has the higher resting heart rate? Explain why this subject’s resting heart rate is higherthan the other subject’s heart rate at rest.
c. Describe the heart rate response for both subjects from rest to maximal levels. Why is there a difference inthe heart rate responses between the subjects?
5. Oxygen uptake involves a number of acute responses which enables oxygen to move from the atmosphere to theskeletal muscle. Outline the role of the following in relation to oxygen uptake:-
a. Pulmonary ventilation __________________________________________________________________
physical activity participation and physiological performance ����������
1. a. Subject A - Trainedb. Subject B
Subject B has a lower stroke volume and less efficient cardiorespiratory system than Subject A . SubjectB’s heart has to beat more rapidly to provide sufficient 0
2.
c. Subject A - lower resting heart rate - heart rate increases slowly during activity and does not reachmaximum levels.Subject B - higher resting heart rate - heart rate increases more rapidly and reaches near maximal levelsduring the activity.Subject A has a higher V0
2 max and is working at a lower percentage of their V0
2 max than subject B.
Subject A has a more efficient cardiorespiratory system than subject B, enabling them to supply and use 02
more efficiently - heart does not have to work as hard to meet exercise demands.
2. Stroke volume increases at the onset of exercise then levels off once maximum strokevolume is attained. Following this cardiac output increases as a result of elevated heart rate.
3. a. Skeletal muscles - Bb. Organs of the body - Ac. Redistribution of cardiac output is possible, due to vasoconstriction of arterioles supplying inactive areas
of the body and vasodilation of arterioles supplying active muscles.
4. a. • 02 Debt - C
• 02 Deficit - A
• Steady State - Bb. Immediate responses which remain until end of exercise:-
• reduced creatine stores• accumulation of lactic acid• increase in muscle temperature• reduction in glycogen stores• redistribution of cardiac output
c. Excess post-exercise oxygen consumption - EPOCd. i. restoration of high energy phosphates
ii. resaturation of myoglobin and haemoglobine. i. Lactate can be resynthesised to glycogen.
ii. Lactate can be used as a metabolic fuel and broken down to provide energy.
5. a. Pulmonary ventilation - minute ventilation increase to move more air - and thus 02 - in and out of the lungs
b. 02 diffusion to blood - vasodilation of capillaries surrounding alveoli enable large volumes of 0
2 to diffuse
into blood and combine with haemoglobin.
c. Cardiac output - stroke volume and heart rate rise to supply more oxygenated blood to working muscles.
d. Blood flow to muscles - redistribution of cardiac output away from organs to working muscles.
e. Myoglobin - facilitates diffusion of oxygen from blood to the mitochondria. Arterio-venous differenceindicates amount of oxygen which has diffused.
f. Mitochondria - contain enzyme systems required for aerobic metabolism. Uses oxygen to produce energyvia the aerobic pathway.
test answers
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