Blood Pressure and Heart Rate Variability Responses to High-Intensity Interval Training in Untrained Postmenopausal Women.

: The aim of this study was to analyze the blood pressure (BP) and heart rate variability (HRV) responses in untrained postmenopausal women submitted to acute single sessions of high-intensity interval training (HIT). : Sixteen postmenopausal women (59.9 ± 5.6 years, 26.7 ± 3.0 kg/m) participated in a random order of two acute sessions in a balanced crossover format: control without exercise in sitting position or HIT session. BP and heart rate (HR) were recorded before and during 60 min following the sessions. : Diastolic (DBP), mean BP (MBP), and double product (DPO) showed interaction ( < .01). DBP, MBP, and DPO increased ( < .01) after HIT but not after the control session. The area under the curve (AUC) of DBP ( = .02) and DPO ( < .01) were different between conditions. Time and frequency indices of HRV presented interaction ( < .05) which impaired these indices post-HIT, but not post-control. The AUC of time and frequency HRV indices were different between conditions. : A single session of HIT may increase BP and cardiac stress and cause perturbation of the autonomic function in untrained postmenopausal women.