Cardiorespiratory Adaptations to Training

1. Cardiorespiratory Adaptations to Training Chapter 13

2. Cardiorespiratory endurance • refers to your body’s ability to sustain prolonged, rhythmical exercise.

3. Cardiorespiratory Endurance • Highly related to aerobic development.

4. Cardiorespiratory Endurance • VO2MAX is the best indicator of cardiorespiratory endurance.

5. VO2MAX • Absolute and relative measures. • absolute =l . min-1 • relative = ml . kg-1 . min-1 • VO2 = SV x HR x a-vO2diff

6. Cardiovascular Response • Left ventricle undergoes the most change in response to endurance training. • internal dimensions of the left ventricle increase. • (mostly in response to an increase in ventricular filling)

7. Cardiovascular Response • left ventricle wall thickness also increases, increasing the strength potential of that chamber’s contractions. Left Ventricle

8. Cardiovascular Response • Following endurance training, stroke volume increases during rest, submaximal levels of exercise, and maximal exertion.

9. Cardiovascular Response • A major factor leading to the stroke volume increase is an increased end-diastolic volume, probably caused by an increase in blood plasma.

10. Cardiovascular Response • Another major factor is increased left ventricular contractility. • This is caused by hypertrophy of the cardiac muscle and increased elastic recoil, which results from increased stretching of the chamber with more diastolic filling.

11. Heart Rate Adaptations: • A person’s submaximal HR decreases proportionally with the amount of training completed.

12. Heart Rate Adaptations: • Maximal HR either remains unchanged or decreases slightly with training.

13. Heart Rate Adaptations: • When a decrease occurs, it is probably to allow for optimum stroke volume to maximize cardiac output.

14. Heart Rate Adaptations: • The HR recovery period decreases with increased endurance, making this value well suited to tracking an individual’s progress with training.

15. Heart Rate Adaptations: • However, this is not useful for comparing fitness levels of different people.

16. Heart Rate Adaptations: • Resistance training can also lead to reduced heart rates; however, these decreases are not as reliable or as large as those seen with endurance training.

17. Cardiac Output Adaptations: • Cardiac output at rest or during submaximal levels of exercise remains unchanged or decreases slightly after training.

18. Cardiac Output Adaptations: • Cardiac output at maximal levels of exercise increases considerably. • This is largely the result of the submaximal increase in maximal stroke volume.

19. Blood Distribution Adaptations • Blood flow to muscles is increased by endurance training.

20. Blood Distribution Adaptations • Increased blood flow results from four factors: • Increased capillarization. • Greater opening of existing capillaries. • More effective blood redistribution. • Increased blood volume.

21. Blood Pressure Adaptations: • Resting blood pressure is generally reduced by endurance training in those with borderline or moderate hypertension.

22. Blood Pressure Adaptations: • Endurance training has little or no effect on blood pressure during standardized submaximal or maximal exercise.

23. Blood Volume Adaptations: • Blood volume increases as a result of endurance training. • The increase is primarily caused by an increase in blood plasma.

24. Blood Volume Adaptations: • RBC count can increase, but the gain in plasma is typically much higher, resulting in a relatively greater fluid portion of the blood.

25. Blood Volume Adaptations: • Increased plasma volume causes decreased blood viscosity, which can improve circulation and oxygen availability.

26. Blood Volume Adaptations: • The training-induced increase in plasma volume, and its impact on stroke volume and VO2MAX, make it one of the most significant training effects.

27. Pulmonary Adaptations: • Most static lung volumes remain essentially unchanged after training.

28. Pulmonary Adaptations: • Tidal volume, though unchanged at rest and during submaximal exercise, increases with maximal exertion.

29. Pulmonary Adaptations: • Respiratory rate remains steady at rest, can decrease slightly with submaximal exercise, but increases considerably with maximal exercise after training.

30. Pulmonary Adaptations: • The combined effect of increased tidal volume and respiration rate is an increase in pulmonary ventilation at maximal effort following training.

31. Pulmonary Adaptations: • Pulmonary diffusion at maximal work rates increases, probably because of increased ventilation and increased lung perfusion.

32. Pulmonary Adaptations: • a-vO2diff increases with training, reflecting an increased oxygen extraction by the tissues and more effective blood distribution.

33. Acid-Base Balance Adaptations: • Lactate threshold increases with endurance training, which allows you to perform at higher rates of work and levels of oxygen consumption without increasing your blood lactate above resting levels.

34. Acid-Base Balance Adaptations: • Maximal blood lactate levels can be increased slightly.

35. Oxygen Consumption Adaptations: • The respiratory exchange ratio decreases at submaximal work rates, indicating a greater utilization of free fatty acids. • It increases at maximal effort.

36. Oxygen Consumption Adaptations: • Oxygen consumption can be increased slightly at rest. • It can be decreased slightly or remain unaltered during submaximal exercise.

37. Oxygen Consumption Adaptations: • VO2MAX increases substantially following training, but the amount of increase possible is limited in each individual.

38. Oxygen Consumption Adaptations: • The major limiting factor appears to be oxygen delivery to the active muscles.

39. Oxygen Consumption Adaptations: • Although VO2MAX has an upper limit, endurance performance can continue to improve for years with continued training.

40. Oxygen Consumption Adaptations: • An individual’s genetic makeup predetermines a range for his/her VO2MAX, accounting for 25% to 50% of the variance in VO2MAX values.

41. Oxygen Consumption Adaptations: • Heredity also largely explains individual variations in response to identical training programs.

42. Oxygen Consumption Adaptations: • Age-related decreases in aerobic capacity might partly result from decreased activity.

43. Oxygen Consumption Adaptations: • Highly conditioned female endurance athletes have VO2MAX values only about 10% lower than those of highly conditioned male endurance athletes. • Body size • Hemoglobin content • Percent lean mass

44. Oxygen Consumption Adaptations: • To maximize cardiorespiratory gains, training should be specific to the type of activity the exerciser usually performs.

45. Oxygen Consumption Adaptations: • Resistance training in combination with endurance training does not appear to restrict improvement in aerobic capacity and may increase short-term endurance.

46. Oxygen Consumption Adaptations: • All exercisers can benefit from maximizing their endurance.

47. Determining Exercise Intensity For basic health and fitness: • 40-45% of heart rate or VO2 reserve, or 50-64% of heart rate max

48. Determining Exercise Intensity For optimal health and fitness: • 50-85% of heart rate or VO2 reserve, or 65-90% of heart rate max

49. Determining Exercise Intensity • Heart rate max Calculated by 208 – 0.7(age)

50. Determining Exercise Intensity • Heart Rate Reserve Heart rate max – resting heart rate • VO2 Reserve VO2max – resting VO2