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 language | English (US) |
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Pages (from-to) | 48-52 |
Number of pages | 5 |
Journal | European Journal of Applied Physiology and Occupational Physiology |
Volume | 67 |
Issue number | 1 |
DOIs | |
State | Published - Jul 1993 |
Externally published | Yes |
Keywords
- Doppler echocardiography
- Isometric exercise
- Stroke volume
ASJC Scopus subject areas
- Physiology
- Public Health, Environmental and Occupational Health