Cardiovagal baroreflex sensitivity
Spontaneous cardiovagal baroreflex sensitivity (cvBRS) was determined from beat-to-beat changes in R–R interval (RRI) and SBP using an analysis software (Beatscope, version 1.1, Finapres Medical Systems, Amsterdam, The Netherlands). Three or more beats of progressive SBP changes and corresponding changes of RRI were identified as baroreflex sequences. Both were recorded in the present study. The minimum criteria for accepting a sequence were set at 1 mmHg for SBP and 4 ms for RRI. The slope of the linear correlation between RRI and SBP was assessed for up–up (progressive increases of SBP followed by a lengthening of the RRI) and down–down (progressive decreases of SBP with a subsequent shortening of the RRI) cvBRSs, which was determined if the r-value was > 0.8. Both cvBRSs were averaged for each participant for the last 5 min of 10-min rest [