Biomedical subjects

Y Nurhayati

Publications and source records attributed to Y Nurhayati.

3 recordsLinked to original sources

PubMed2001

Cardiovascular response of trained and untrained old men to mental challenge.

PURPOSE: The cardiovascular response to mental challenge of trained and untrained older men was examined. METHODS: Blood pressure, heart rate, stroke volume, cardiac output, total peripheral resistance (TPR), rate pressure product, and cardiac contractility of 10 aerobically trained (trained) and 10 untrained (untrained) older men during and recovering from the Stroop task were compared. Fitness was assessed by online, open-circuit spirometry using a bicycle ergometer. RESULTS: Trained compared with untrained men showed significantly lower absolute heart rate during and recovering from the Stroop and greater left ventricular ejection time recovering from Stroop. Delta TPR scores were greater for Trained during and recovering from the Stroop, whereas delta systolic blood pressure was greater recovering from Stroop. CONCLUSION: These results indicate that although aerobically trained men possessed lower absolute heart rate their change in TPR and systolic blood pressure during mental challenge was significantly greater than that of untrained older men. The greater vascular response of the trained to mental challenge may reflect greater sensitivity to alpha-adrenergic stimulation.

Aged↗

PubMed1998

Cardiovascular response to passive cycle exercise.

PURPOSE: Cardiovascular response of trained males (N = 20) and fit but untrained controls (N = 10) were examined during rest and passive cycle exercise (PCE). METHODS: Heart rate (HR), stroke volume (SV), cardiac output (CO), total peripheral resistance (TPR), and mean arterial pressure (MAP) were measured during PCE for 6 min at intensities of 30 and 60 rpm. Also vagal influence on the heart was assessed through time series analysis of heart period variability (HPVts) at high and medium frequencies. Electromyography (EMG) was used to monitor muscle activity during PCE. RESULTS: During PCE no differences in cardiovascular response were found between the trained and untrained groups; thus groups were combined for the remainder of the analysis. Results indicated that during light and medium PCE all subjects combined showed a significant increase in HR, CO, and MAP and a significant decrease in HPVts (P < 0.001). CONCLUSION: The increase in HR during passive exercise may be a result of the stimulation of mechanoreceptors. The small and similar SV response during PCE of both groups suggests that the muscle pumps may not be effective during this form of passive exercise.

Adolescent↗

PubMed1997

Stroke volume response to cycle ergometry in trained and untrained older men.

UNLABELLED: The aims of this study were threefold: (1) to investigate the stroke volume (SV) response of trained older male cyclists [Cyclists: 65 (2.1) years, n = 10] during incremental cycle ergometry (20 W.min-1); (2) to determine the SV dynamics and total peripheral resistance response of untrained, but healthy and active older male controls [ CONTROLS: 66 (1.1) years; n = 10]; (3) to compare the maximum oxygen consumption (VO2max) and SV response of trained older male runners [Runners: 65 (3.4) years; n = 11] with that of age-matched Cyclists. Impedance cardiography was used to assess the response of cardiac output (CO), SV and total peripheral resistance to exercise involving cycle ergometry. The mean VO2max of the trained Cyclists [54 (1.6) ml.kg-1.min-1] was significantly higher (P < 0.05) than that of the Runner [48 (3.9) ml.kg-1.min-1], whereas both groups possessed a significantly higher VO2max than the CONTROLS [28 (1.3) ml.kg-1.min-1]. During exercise, at a heart rate of 90 beats.min-1, the SV of the Cyclists increased by 41%, that of the Runners increased by 47%, and that of the CONTROLS increased by 31%. However, the Cyclists' and Runners' SV response was significantly greater than that of the CONTROLS. The SV for cyclists and controls peaked at 30% of VO2max. This early increase in SV was a major factor underlying the increase in CO during exercise in both the trained and the untrained subjects. In addition, all three groups showed a significant decrease in total peripheral resistance throughout exercise. The finding that older male runners possessed a large exercise SV and high VO2max suggests that run training results in enhanced cardiovascular performance during cycle ergometry.

Aged↗