The effect of aerobic fitness on the cardiovascular and sympathetic nervous system response to physiological stress at rest and during dynamic exercise

  • Author / Creator
    Raymond, Duncan A
  • A cardio-protective adaptation associated with aerobic fitness may be an attenuated sympathetic nervous system (SNS) and cardiovascular response to stress. The hypothesis that the cardiovascular and SNS responses to physiological stress at rest and during exercise would be a function of maximal aerobic capacity (VO2max) was investigated. Young males performed ramp cycling exercise to determine VO2max and were then assigned to low (n=8), mid (n=8) and high (n=7) aerobic fitness groups. The physiological responses to a cold-pressor test and isometric handgrip exercise were measured at rest and during moderate- and heavy-intensity knee-extension (KE) exercise. Highly fit subjects had lower resting muscle sympathetic nerve activity (MSNA), but a larger MSNA response to physiological stress at rest. The cardiovascular response to stress at rest or during KE exercise was not altered by aerobic fitness. Heavy-intensity KE exercise attenuated leg vasoconstriction in response to physiological stress by a similar magnitude in all groups.

  • Subjects / Keywords
  • Graduation date
  • Type of Item
  • Degree
    Master of Science
  • DOI
  • License
    This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.
  • Language
  • Institution
    University of Alberta
  • Degree level
  • Department
    • Physical Education and Recreation
  • Supervisor / co-supervisor and their department(s)
    • DeLorey, Darren (Physical Education and Recreation)
  • Examining committee members and their departments
    • Kennedy, Michael (Physical Education and Recreation)
    • McCargar, Linda (Agricultural, Food and Nutritional Science)