Fig. 2.

The top part shows measured values of heart rate (left panel) and of quasi-normalised high frequency HRV components (right panel) during pre-specified 5-min windows of the postural tests. In each panel, the left and right parts correspond to the postural tests 1 and 2, respectively. The positions are listed under the panels (the order of the two standing positions corresponds to their sequence within the tests – see the text for details). In each panel, the red and blue lines correspond to female and male subjects, respectively. The coloured dots show the means of the sex-specific sub-population, the error bars show the 95% confidence intervals of the means. The bottom part shows the cumulative frequency distributions of 5-min measurements of heart rate (left panels) and of quasi-normalised high frequency components (right panels) during initial supine positions (fine lines), sitting positions (middle-width lines) and final 5-min of standing positions (bold lines). The data presented are the intra-subject averages of both postural tests. The read and blue panels correspond to female and male sub-populations, respectively. Light and dark shaded areas highlight the shifts between supine and sitting positions, and between the sitting and standing positions, respectively. Note that the extent of dark shaded areas is similar between the sex groups for heart rate but not for quasi-normalised high-frequency HRV components.