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

  • Physiological stress
  • Sympathetic nervous system
  • VO2max
  • Exercise
  • Blood pressure
  • Vascular conductance
  • Vasoconstriction

• Graduation date

  Fall 2012

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/R3XH3J

• 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.