Table 2. Descriptive statistics of badminton players’ HR, HRR- as well as HRV-related variables over different time periods. Data are means (±SD). HRV- and HRR-related variables Pre-match In-match In-match rest Post-match HRV-related variables Mean R-R 457.7 (54.8) 354.2 (28.5) 364.1 (46.1) 381.5 (52.2) Ln-SDNN 3.72 (.80) 3.12 (.58) 3.15 (.69) 3.24 (.62) Ln-RMSSD 3.32 (1.00) 2.43 (.75) 2.25 (1.01) 2.42 (1.01) Peak VLF (Hz) .03 (.01) .03 (.01) .03 (.01) .03 (.01) Peak LF (Hz) .10 (.03) .09 (.03) .09 (.04) .09 (0.04) Peak HF (Hz) .27 (.05) .24 (.04) .21 (.05) .24 (.07) Peak VLF Power (%) 17.6 (14.0) 24.6 (19.1) 31.2 (28.3) 33.4 (28.4) Peak LF Power (%) 28.5 (14.3) 30.1 (10.5) 35.3 (15.8) 29.9 (15.3) Peak HF Power (%) 53.3 (18.8)) 45.0 (19.2) 33.3 (22.9) 36.4 (25.3) Ln-LFnu Power 3.60 (.51) 3.77 (.37) 3.99 (.44) 3.90 (.47) Ln-HFnu Power 4.01 (.38) 3.92 (.32) 3.58 (.55) 3.62 (.66) Ln-LFnu/Ln-HFnu Ratio .92 (.22) .98 (.18) 1.16 (.31) 1.14 (.38) Ln-SD1 3.39 (1.04) 2.66 (.82) 2.23 (1.02) 2.44 (1.14) Ln-SD2 3.82 (.70) 3.26 (.54) 3.38 (.66) 3.45 (.54) HRR-related variable HRR (%) 12.9 (6.3) 14.3 (4.8) HR-related variables HR Minimum (bpm) 115(21) HR Mean (bpm) 167(14) HR Maximum (bpm) 193(11)