Table 2. Correlation (r) matrix of elite volleyball referees’ cardiac responses with other measures HR pre-match HR post-match Ø HR during the match HRV pre-match HRV post-match Ø HRV during the match State anxiety pre-match -0.17 -0.29 -0.23 0.16 0.07 0.12 State anxiety post-match 0.03 0.00 0.14 -0.27 -0.26 -0.30 Trait anxiety -0.05 -0.06 -0.03 -0.18 -0.17 -0.26 Problematic single decisions -0.21 0.04 0.11 -0.36 * -0.29 -0.16 Fear of physical harm -0.09 -0.10 -0.26 0.02 -0.12 0.04 Technical error -0.09 0.00 -0.14 -0.17 -0.32 0.05 Social conflicts -0.05 0.14 0.10 -0.11 -0.10 -0.08 Observation pressure -0.04 -0.02 0.06 -0.20 -0.07 -0.14 BOSSS Total -0.20 -0.10 -0.03 -0.17 -0.10 -0.14 * indicates p < 0.05.