Cardiovascular responses to sustained maximal isometric contractions of the finger flexors

D. L. Smith, J. E. Misner, D. K. Bloomfield, L. K. Essandoh

Research output: Contribution to journalArticle

Abstract

This study investigated cardiovascular responses to 2 min sustained submaximal (20% MVC) and maximal (100% MVC) voluntary isometric contractions of the finger flexors in healthy young women. Cardiovascular variables investigated were: heart rate (fc), mean arterial pressure ( {Mathematical expression}a), and stroke volume (SV). Doppler echocardiography was used to estimate SV from measures of aortic diameter (AD) and time-velocity integrals. Preliminary studies indicated that AD did not change significantly after 2 min sustained 100% MVC. Therefore, pre-exercise AD values were used to calculate SV before, during and after exercise. During the 2-min 100% MVC period, fc and {Mathematical expression}aincreased significantly during the first 30 s of contraction. fc then remained constant during the remainder of the 2-min contraction period, while {Mathematical expression}acontinued to rise. SV did not change significantly during the 100% MVC task but increased significantly during recovery from sustained 100% MVC. The data suggest that the magnitude of cardiovascular responses to isometric exercise is dependent on the specific task performed, and that there is a different pattern of response for fc, {Mathematical expression}a, and SV during 20% and 100% MVC tasks. Unlike fc and {Mathematical expression}a, SV did not change significantly during isometric exercise, but increased significantly after sustained 100% MVC.

Original languageEnglish (US)
Pages (from-to)48-52
Number of pages5
JournalEuropean Journal of Applied Physiology and Occupational Physiology
Volume67
Issue number1
DOIs
StatePublished - Jul 1 1993
Externally publishedYes

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Keywords

  • Doppler echocardiography
  • Isometric exercise
  • Stroke volume

ASJC Scopus subject areas

  • Physiology
  • Public Health, Environmental and Occupational Health

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