THE RELATIONSHIP BETWEEN AEROBIC TRAINING AND CARDIOVASCULAR RESPONSE TO EXERCISE

Exercise-induced hypervolemia has been proposed to be an important determinant of cardiac and vascular adaptations to aerobic training. In order to examine the relationship between hypervolemia and cardiovascular adaptations to aerobic exercise a series of cross-sectional and longitudinal studies were performed. Study 1 examined cardiovascular response of trained runners (n=15) and untrained males (n=l 5) at rest and during exercise while venous return was restricted by venous occlusion. In Study 2, the peripheral vascular capacity of trained runners (n=10) and untrained males (n=10) was compared. In Study 3 the effect of short-term training-induced plasma volume expansion on the cardiac and peripheral vascular capacity of untrained males (n=14) was examined. Impedance cardiography was used to examine stroke volume and cardiac output, whereas resting and peak blood flow were assessed using plethysmography. In Study 1 results showed that trained compared to untrained males had significantly lower resting heart rate and higher resting upright stroke volume. During cycle exercise both groups had similar increases in heart rate and decreases in stroke volume in response to venous occlusion. Also, during cycle exercise, heart rate and stroke volume were significantly higher at high cadence (80 rpm) than that at low cadence (40 rpm). In Study 2 results showed that the trained compared to untrained had significantly higher peak forearm and leg blood flow, and higher forearm and leg vasodilatory and venous capacity. In Study 3, twenty-four hours after the short-term intense training bout, there was a significant increase in blood (4.6%) and plasma volume (7.7%). Contrary to the hypotheses, however, hypervolemia did not result in any change in resting heart rate, stroke volume, and vascular variables, although exercise heart rate was decreased significantly. In summary, results of Studies 1 and 2 confirm that aerobic training is associated with enhanced resting and exercise cardiac and vascular response. Results of Study 3 suggest that an exercise-induced plasma volume expansion of 7.7% does not bring about major cardiac or vascular changes at rest or during cycle ergometry exercise.

Name dc:type.qualificationname

PhD

Level dc:type.qualificationlevel

Doctoral

Grantor dc:publisher.institution

De Montfort University

Year dc:date.issued

2001

Author dc:creator

• NURHAYATI, YATI

Licence

• https://dora.dmu.ac.uk/bitstreams/9f02c7e0-1dce-4e1c-a2d1-ab49720b2eac/download