1. Functional Capacity of the Cardiovascular System
Chapter 17
Functional Capacity of the Cardiovascular System
Copyright © 2007 Lippincott Williams & Wilkins.
McArdle, Katch, and Katch: Exercise Physiology: Energy, Nutrition, and Human Performance, Sixth Edition

2. Cardiac Output Cardiac output (Q) = HR × SV Methods of Measuring Q
Direct Fick
Indicator dilution
CO2 rebreathing
Copyright © 2007 Lippincott Williams & Wilkins.
McArdle, Katch, and Katch: Exercise Physiology: Energy, Nutrition, and Human Performance, Sixth Edition

3. Direct Fick Method a- O2 difference Q = O2 mL · min−1
Copyright © 2007 Lippincott Williams & Wilkins.
McArdle, Katch, and Katch: Exercise Physiology: Energy, Nutrition, and Human Performance, Sixth Edition

4. Copyright © 2007 Lippincott Williams & Wilkins.
McArdle, Katch, and Katch: Exercise Physiology: Energy, Nutrition, and Human Performance, Sixth Edition

5. Indicator Dilution Method
Q = Quantity of dye injected
Average dye
concentration blood × Duration of curve
for duration of curve
Copyright © 2007 Lippincott Williams & Wilkins.
McArdle, Katch, and Katch: Exercise Physiology: Energy, Nutrition, and Human Performance, Sixth Edition

6. CO2 Rebreathing Method -aCO2 difference Q = CO2 × 100
Copyright © 2007 Lippincott Williams & Wilkins.
McArdle, Katch, and Katch: Exercise Physiology: Energy, Nutrition, and Human Performance, Sixth Edition

7. Cardiac Output at Rest Values vary depending upon emotional state.
Average male ~5 L · min-1
Average female ~4 L · min-1
Copyright © 2007 Lippincott Williams & Wilkins.
McArdle, Katch, and Katch: Exercise Physiology: Energy, Nutrition, and Human Performance, Sixth Edition

8. Untrained Characteristics of Q
HR ~ 70 BPM
SV ~ 71.4 mL
Average women ~25% lower due to smaller size
Copyright © 2007 Lippincott Williams & Wilkins.
McArdle, Katch, and Katch: Exercise Physiology: Energy, Nutrition, and Human Performance, Sixth Edition

9. Endurance Athletes Characteristics of Q Mechanisms HR ~ 50 BPM
SV ~ 100 mL
Mechanisms
Increased vagal tone w/decreased sympathetic drive
Increased blood volume
Increased myocardial contractility and compliance of left ventricle
Copyright © 2007 Lippincott Williams & Wilkins.
McArdle, Katch, and Katch: Exercise Physiology: Energy, Nutrition, and Human Performance, Sixth Edition

10. Cardiac Output During Exercise
Q increases rapidly during transition from rest to exercise.
Q at max exercise increases up to 4 times.
Q HR SV
Untrained 22 L mL
Trained 35 L mL
Copyright © 2007 Lippincott Williams & Wilkins.
McArdle, Katch, and Katch: Exercise Physiology: Energy, Nutrition, and Human Performance, Sixth Edition

11. Stroke Volume: Diastolic Filling vs. Systole Emptying
Mechanisms for increased SV with training
Increased blood volume – increase diastolic filling
Increased preload – Starling’s Law of the Heart
Increased Contractility – greater systolic emptying
Copyright © 2007 Lippincott Williams & Wilkins.
McArdle, Katch, and Katch: Exercise Physiology: Energy, Nutrition, and Human Performance, Sixth Edition

12. Cardiovascular Drift Results from HR drifts upward to maintain same Q
Dehydration
Reduction in SV
HR drifts upward to maintain same Q
Copyright © 2007 Lippincott Williams & Wilkins.
McArdle, Katch, and Katch: Exercise Physiology: Energy, Nutrition, and Human Performance, Sixth Edition

13. Cardiac Output Distribution
Blood flows to tissues in proportion to their metabolic activity.
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McArdle, Katch, and Katch: Exercise Physiology: Energy, Nutrition, and Human Performance, Sixth Edition

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McArdle, Katch, and Katch: Exercise Physiology: Energy, Nutrition, and Human Performance, Sixth Edition

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McArdle, Katch, and Katch: Exercise Physiology: Energy, Nutrition, and Human Performance, Sixth Edition

16. Cardiac Output and Oxygen Transport
Rest
Q = 5 L · min-1
O2 transport = 1,000 mL – 200 mL/L blood
Copyright © 2007 Lippincott Williams & Wilkins.
McArdle, Katch, and Katch: Exercise Physiology: Energy, Nutrition, and Human Performance, Sixth Edition

17. Exercise Max Q averages ~ 16 L · min-1 O2 transport = 200 mL/L blood
Result
3200 mL O2
Training enables Q to increase up to 40 L · min-1, increasing O2 transport up to 8,000 mL.
Copyright © 2007 Lippincott Williams & Wilkins.
McArdle, Katch, and Katch: Exercise Physiology: Energy, Nutrition, and Human Performance, Sixth Edition

18. Close Association Between Max Q and O2max
An almost proportionate increase in max Q accompanies increases in O2max with training.
Copyright © 2007 Lippincott Williams & Wilkins.
McArdle, Katch, and Katch: Exercise Physiology: Energy, Nutrition, and Human Performance, Sixth Edition

19. Copyright © 2007 Lippincott Williams & Wilkins.
McArdle, Katch, and Katch: Exercise Physiology: Energy, Nutrition, and Human Performance, Sixth Edition

20. Cardiac Output Differences: Men, Women, and Children
Women have a 10% lower hemoglobin level than men.
Result is a 5 – 10% increase in Q at any submax level of O2 consumption
Children have higher HR
Result is smaller Q, expanded a- O2
Copyright © 2007 Lippincott Williams & Wilkins.
McArdle, Katch, and Katch: Exercise Physiology: Energy, Nutrition, and Human Performance, Sixth Edition

21. O2 Extraction: The a- O2 Difference
O2 consumption increases during exercise.
Increases Q
Increases extraction of O2 by tissues
O2 = Q x a- O2 difference
Copyright © 2007 Lippincott Williams & Wilkins.
McArdle, Katch, and Katch: Exercise Physiology: Energy, Nutrition, and Human Performance, Sixth Edition

22. a- O2 Difference during Rest
20 mL O2 · dL-1 arterial blood
15 mL O2 · dL-1 venous blood
5 mL a- O2diff
Copyright © 2007 Lippincott Williams & Wilkins.
McArdle, Katch, and Katch: Exercise Physiology: Energy, Nutrition, and Human Performance, Sixth Edition

23. a- O2 Difference during Exercise
20 mL O2 · dL-1 arterial blood
5 – 15 mL O2 · dL-1 venous blood
Up to a threefold increase in O2 extraction
Copyright © 2007 Lippincott Williams & Wilkins.
McArdle, Katch, and Katch: Exercise Physiology: Energy, Nutrition, and Human Performance, Sixth Edition

24. Severe Heart Disease Exhibit low ability to improve Q or SV
Skeletal muscle adaptations allow for increased O2 extraction.
Copyright © 2007 Lippincott Williams & Wilkins.
McArdle, Katch, and Katch: Exercise Physiology: Energy, Nutrition, and Human Performance, Sixth Edition

25. Factors Affecting the a- O2 Differences
Redistribution of flow to active tissues during exercise
Increased capillary density due to training increases surface area and O2 extraction
Increased number and size of mitochondria
Increased oxidative enzymes
Vascular and metabolic improvements
Copyright © 2007 Lippincott Williams & Wilkins.
McArdle, Katch, and Katch: Exercise Physiology: Energy, Nutrition, and Human Performance, Sixth Edition

26. Cardiovascular Adjustments to Upper-Body Exercise
Max O2 consumption
Upper-body exercise results in max O2 consumption ~20 – 30% lower than lower-body exercise.
Higher O2 consumption for a given submax workload
Lower mechanical efficiency
Muscular effort to stabilize torso
Copyright © 2007 Lippincott Williams & Wilkins.
McArdle, Katch, and Katch: Exercise Physiology: Energy, Nutrition, and Human Performance, Sixth Edition

27. Copyright © 2007 Lippincott Williams & Wilkins.
McArdle, Katch, and Katch: Exercise Physiology: Energy, Nutrition, and Human Performance, Sixth Edition

28. Physiologic Response Submaximal arm exercise produces > HR
> Pulmonary ventilations
> RPE
> BP response
than comparable leg exercise
Copyright © 2007 Lippincott Williams & Wilkins.
McArdle, Katch, and Katch: Exercise Physiology: Energy, Nutrition, and Human Performance, Sixth Edition

29. Physiologic Response
Exercise prescription for arm exercise should not be based on values obtained from lower-body exercises.
Copyright © 2007 Lippincott Williams & Wilkins.
McArdle, Katch, and Katch: Exercise Physiology: Energy, Nutrition, and Human Performance, Sixth Edition