Table 6. Correlation (r) matrix of elite volleyball referees’ BOSSS-D responses with other measures. Problematic single decisions Fear of physical harm Technical error Social conflicts Observation pressure BOSSS Total HR pre-match -0.21 -0.09 -0.09 -0.05 -0.04 -0.20 HR post-match 0.04 -0.10 0.00 0.14 -0.02 -0.10 Ø HR during the match 0.11 -0.26 -0.14 0.10 0.06 -0.03 HRV pre-match -0.36 * 0.02 -0.17 -0.11 -0.20 -0.17 HRV post-match -0.29 -0.12 -0.32 -0.10 -0.07 -0.10 * indicates p < 0.05.