Fig. 3

Summary of the effects of the two challenges, namely the Valsalva maneuver (VM) and the deep breathing challenge (DB) on the heart rate variability (HRV) parameters of the study sample, in comparison to the baseline values (BL). The variables displayed on the graph are box plots of the raw values. The interpretation of the HRV parameters is detailed in Table 1. The symbols ‘#’ and ‘$’ signal a significant difference (p < 0.05), respectively with baseline and between VM and DB (see Methods’ chapter for detailed description of the statistics). The aggregated data are detailed in the Supplementary Table 1