The document discusses the cardiopulmonary changes that occur during exercise, emphasizing the physiological responses of the cardiovascular and respiratory systems. It outlines types of exercises, the grading of exercise intensity, and the acute and long-term adaptations of the body in response to training, including increased heart rate, stroke volume, and oxygen uptake. Additionally, the document highlights the importance of factors like redistribution of blood flow and ventilatory responses as exercise intensity increases.

1. Cardiopulmonary changes in Exercise
Dr Rajesh P
Associate Professor
Department of Physiology
Mediciti IMS

2. Introduction
• Exercise is physical activity that is planned, structured
and repetitive for the purpose of conditioning any part of
the body.
• Exercise is used to improve health, maintain fitness and
is important as a means of physical rehabilitation.

3. Primary aim of the exercise
• In the heart: to supply adequate oxygenated blood to
the exercising muscle
• In the lungs: to facilitate oxygen consumption of the
body
- To meet the metabolic demand during exercise.

4. Types of exercise
• Flexibility. E: shoulder and upper arm stretch, calf
stretch
• Endurance. E: brisk walking, jogging, swimming
• Strength. E: lifting weights
• Balance. E: standing on one foot, heal-to-toe walk

5. Grading of exercise
Grade Level HR(beats /
min)
O2consumption(L
/min)
I Light (mild) < 100 0.4 – 0.8
II Moderate 100 - 125 0.8 – 1.6
III Heavy 125 – 150 1.6 – 2.4
IV Severe >150 >2.4

6. Changes during exercise
• Training effects are the physiological changes your body
makes in response to the demands of the exercise you
perform.
There are 2 kinds of responses to training:
• Acute (immediate) – last only for the duration of the
exercise & the recovery period.
• Chronic – long-term adaptations & take about 6 weeks
of training to develop.

7. Changes in exercise
Systems
CVS RS
Short term Short term
Long term Long term

8. CVS
Short term Long term
Increased HR, BP Cardiac hypertrophy
Increased SV, CO
Increased skeletal muscle
blood flow
Redistribution of blood
flow
Lower resting heart rate
Increase in RBCs,
Capillaries

9. RS
Short term Long term
Increase in RR, TD Increased ventilation
Increased ventilation Increased lung capacity
Increased VO2 Increased strength of intercostal
muscles
Increased oxygen diffusion rate
Increased minute ventilation
Increased number of capillaries
and alveoli
Increased lactate threshold

10. CVS Responses to exercise
• Skeletal muscle blood flow
• Redistribution of blood flow
• Cardiac output changes
• Blood pressure changes
• Blood volume changes

11. Cardiovascular Response to Exercise
• Increased heart rate / cardiac output
• Anticipatory response (increased heart rate before
exercise)
– Caused by the release of epinephrine
• Steady state heart rate: during steady exercise
• Maximum heart rate = 220 - age

12. Skeletal muscle blood flow
• Blood flow increased by arteriolar dilatation and opening
up of closed capillaries.
Local factors: autoregulation
Neural factors: sympathetic
Humoral factors: adrenaline
Sympatho – adrenaline discharge induces an increase in
muscle blood flow in anticipation of exercise and
adrenaline sustains the increased blood flow during and
beyond the exercise.

13. Redistribution of Blood Flow During Exercise
• Increased blood flow to working skeletal muscle
– At rest, 15–20% of cardiac output to muscle
– Increases to 80–85% during maximal exercise
• Decreased blood flow to less active organs
– Liver, kidneys, GI tract
• Redistribution depends on metabolic rate
– Exercise intensity

14. • Redistribution of blood to the skin in order to maintain
body temperature.
• Increased metabolic rate of working muscles
• Autoregulation: intrinsic control of blood flow by
changes in local metabolites (e.g., oxygen tension, pH,
potassium, adenosine, and nitric oxide) around arterioles.
• Cardiovascular drift: increased H.R. compensates for a
decreased S.V. from a decreased total blood volume to
maintain Q.
– redistribution
– decreased blood plasma

15. Redistribution of Blood Flow During Exercise

16. Changes in Muscle and Splanchnic Blood Flow
During Exercise

17. Regulation of Local Blood Flow During Exercise
• Skeletal muscle vasodilation
– Autoregulation
• Blood flow increased to meet metabolic
demands of tissue
• Due to changes in O2 tension, CO2 tension,
nitric oxide, potassium, adenosine, and pH
• Vasoconstriction to visceral organs and inactive
tissues
– SNS vasoconstriction

18. Oxygen Delivery During Exercise
• Oxygen demand by muscles during exercise is
15–25x greater than at rest
• Increased O2 delivery accomplished by:
– Increased cardiac output
– Redistribution of blood flow
• From inactive organs to working skeletal
muscle

19. Changes in Cardiac Output During Exercise
• Cardiac output increases due to:
– Increased HR
• Linear increase to max
– Increased SV
• Increase, then plateau at ~40% VO2 max
• No plateau in highly trained subjects
Max HR = 220 – age (years)

20. Stroke Volume

21. Heart rate
• Increased heart rate
• Anticipatory response
(increased heart rate
before exercise)
– Caused by the
release of
epinephrine
• Steady state heart
rate: during steady
exercise

22. Cardiac output
• No change at
rest
• No change at
submax exercise
• Increased at
maximal
exercise

23. The cardiac cycle at rest and
during exercise

24. Changes in Arterial-Mixed Venous O2 content
during exercise
• Higher arteriovenous difference (a-vO2 difference)
– Amount of O2 that is taken up from 100 ml blood
– Increase due to higher amount of O2 taken up
• Used for oxidative ATP production
• Fick equation
– Relationship between cardiac output (Q), a-vO2
difference, and VO2
VO2 = Q X a-vO2 difference

25. Blood Pressure
SBP increases in direct proportion to increase in exercise intensity
As exercise begins the baroreceptors detect a decrease in BP specifically SBP
◦ The CNS responds by constricting blood vessels and increasing SBP and further
increases HR
◦ Eventually the CNS detects that SBP needs to be reduced and is reduced via the
vasodilation of the vessels.
◦ The CNS will continue to attempt to regulate BP throughout exercise until maximal
levels are reached
◦ DBP does not change significantly (may even decrease)
◦ Therefore little change in MAP

26. Blood pressure response to exercise
Systolic- Maximum
pressure
Diastolic- Minimum
pressure

27. Isotonic exercise
Moderate
exercise
SBP ↑
DBP unaltered
Severe exercise
Vasodilatation
caused by
metabolites
↓ Peripheral
resistance
SBP↑↑
DBP ↓

28. Isometric exercise
Peripheral
resistance↑
SBP + DBP ↑

29. BP changes in Exercise
• Systolic B.P. increases with intensity
– Valsalva during resistance exercise
– (moderately forceful attempted exhalation against
a closed airway, usually done by closing one's
mouth, pinching one's nose shut while expelling
air out as if blowing up a balloon)
– increased use of upper body musculature
• Diastolic B. P. does not change

30. Changes in Blood volume
• Increased total blood
volume
• Increased plasma
volume
• Increased red blood
cells
• Decrease in
hematocrit (44 to 41)

31. Myocardial Hypertrophy
Aerobic training: Thicker walls and greater
volume
Strength training: Thicker walls only
Pathological: Thicker but weaker walls

32. Transition from rest to exercise and exercise to
recovery
• At the onset of exercise:
– Rapid increase in HR, SV, cardiac output
– Plateau in submaximal (below lactate threshold)
exercise
• During recovery
– Decrease in HR, SV, and cardiac output toward
resting
– Depends on:
• Duration and intensity of exercise
• Training state of subject

33. Transition From Rest to Exercise to Recovery

34. Summary of Cardiovascular Responses to
Exercise

35. Acute cardiovascular responses to exercise
•  heart rate
•  stroke volume
•  cardiac output
•  blood pressure
•  blood flow
•  blood plasma volume

36. Long-term effects of exercise - Heart
• Larger, stronger heart chambers
• Stronger heart beat – more efficient circulation
• Lower resting heart rate – greater capacity for work
• Stroke volume – can be double that of an untrained
athlete
• Cardiac output – larger stroke volume increases the
blood processed per minute

37. Circulatory system
• Arteries become larger and more elastic
• Blood pressure reduced
• More red blood cells produce more haemoglobin
• Lower levels of fat in the blood as the body has learned to
utilise it as fuel
• Increased capacity to process lactic acid during exercise

38. Respiratory changes in exercise

39. Before expected exercise begins, ventilation rises
• 'emotional hyperventilation‘
• at any rate, impulses descending from the cerebral
cortex are responsible

40. How does pulmonary ventilation (breathing)
increase during exercise?
1. During light exercise (walking)?
By increasing the tidal volume (breathing deeper)
2. During intense exercise (sprinting)?
By increasing the frequency of breathing
3. During steady state exercise (jogging)?
By increasing both the tidal volume and the frequency
of breathing

41. • during dynamic exercise
of increasing intensity,
ventilation increases
linearly over the mild to
moderate range, then more
rapidly in intense exercise
• the workload at which
rapid ventilation occures is
called the ventilatory
breakpoint (together with
lactate threshold)
Respiration during exercise
Lactate acidifies the blood, driving off CO2 and increasing ventilatory rate

43. Factors which stimulate increased ventilation
during exercise
• neural input from the motor areas of the cerebral cortex
• proprioceptors in the muscles and joints
•  body temperature
• circulating NE and E
•
• pH changes due to lactic acid
• changes in pCO2 and O2 do not play significant role
during exercise

44. Lung volumes

45. Lung capacities

46. Immediate changes during exercise on RS
a) Tidal Volume: increases depending on intensity, it may
be 1500-2000 ml for ordinary person and for well trained
athlete it may be increased to 2500 ml.
b) Respiratory rate: for ordinary persons it may be
increased to 25-30 per minute and for well trained athlete
it may be around 38-40 per minute.
c) Pulmonary Ventilation: both TV and RR increases , PV
will also increase depending on the intensity of exercise .
For ordinary person , the value of PV may be 40-50 lit /
min and for well trained athlete , it may be around 100 lit
/ min.

47. d) Oxygen uptake: The amount of oxygen which we take
inside the body from ambient air in each minute at rest is
called resting oxygen uptake.
It is around 200-300 ml / min .
During exercise oxygen uptake increases to 3.5 lit / min for
ordinary person and 4.5 lit/min for well trained athlete.
.

48. e) Lung diffusion capacity: During exercise there will
be more movement of gas molecules and diffusion
capacity increases.
f) Lung volume: For normal breathing at rest lung
expand and there is a change in air pressure. During
exercise due to rapid movement of diaphragm and
intercostal muscles total area of lung expands to
accommodate more exchange of gases

49. Long-term effect of training on RS
a) Tidal Volume (TV) : Trained athlete’s capacity to
inhale or exhale air during exercise increases to the tune
of 2500 ml. Untrained persons can not increase up to
this level because their capacity is less than trained
athletes.
b) Respiratory rate (RR) : Trained athlete may increase
their rate to 40 in each minute from 16 / min at rest.
Untrained persons will not be able to reach to this level .
They may increase their rate up to 25-28 / min.

50. • c) Pulmonary ventilation (PV): A trained athlete
may increase PV to around 100 lit/min. This is
because their TV and RR both increases during
exercise. Untrained persons may increase it up to 50-
60 lit/min.
• d) Oxygen uptake: During exercise, after a long term
training , a trained athlete may consume around 5 lit
oxygen per minute. Untrained persons may go up to
the level of 3.5 lit oxygen per minute.

51. e) Lung diffusion capacity: During exercise , the lung
diffusion capacity increases in both trained and untrained
persons. However, trained athletes may increase their
diffusion capacity 30% more than that of an untrained
person because athlete’s lung surface area and red blood
cell count is higher than that of the non-athletes.
f) Vital capacity: For a healthy adult male it is around 4.8
lit and for women 3.1 lit. The athletes who are under
training for a long period may increase vital capacity to
around 6 lit.

52. g) Efficiency of lung: An athlete’s total efficiency of
the lung remain at higher level than the non-athletes.
This efficiency is the key factor for higher rate of
oxygen uptake than non-athletes.
h) Second wind: a sudden transition from an ill-defined
feeling of distress or fatigue during the early portions
of prolonged exercise to a more comfortable, less
stressful feeling later in exercise.
It has been observed that trained athletes get their
second wind comfortably and easily than non-
athletes.

53. VO2 max
• the maximal amount of oxygen that the human body is
able to utilize per minute of strenuous physical activity
• The intensity of exercise performed is defined as a
percentage of VO2max
•  50% of Vo2max – glycogen use less than 50%, FFA use
predominate + small amounts of blood glucose
• >50% of Vo2max – carbohydrate use increases 
glycogen depletion  exhaustion

54. • 70-80% of Vo2max – glygogen depletion after 1.5-2
hrs
• 90-100% of Vo2max – glycogen use is the highest, but
depletion does not occur with exhaustion (pH and 
of metabolites limit performance)

55. Oxygen
consumption
(liters/min)
V02
peak
Work rate (watts)
↑ exercise work  ↑ O2 usage  Person’s max. O2
consumption (VO2max) reached

56. Acute respiratory responses to exercise
During exercise & recovery, more O2 must be delivered
from the lungs to the working muscles, & excess CO2
must be removed from the working muscles.
•  respiratory rate
•  tidal volume
•  ventilation
•  lung diffusion
•  O2 uptake, or volume of O2 consumed

57. Long term effects on Breathing
• Lung capacity increased
• Increased number of alveoli in lungs
• This allows a greater volume of air to pass into blood
stream
• We can therefore maintain higher levels of activity
for longer and are less likely to become breathless
when performing normal daily tasks
• Gaseous exchange is improved so that CO2 and other
waste products are removed more efficiently.
• This also improves our anaerobic capacity

58. Cardiorespiratory endurance
• the ability of the heart, lungs and blood vessels to
deliver adequate amounts of oxygen to the cells to meet
the demands of prolonged physical activity
• the greater cardiorespiratory endurance  the greater
the amount of work that can be performed without
undue fatigue
• the best indicator of the cardiorespiratory endurance is
VO2max .

59. Benefits of exercise