Heart rate and heart rate variability variables (mean ± SD) of participants and statistical results.

HR = heart rate; SDNN = standard deviation of normal-to-normal beat; rMSSD = root mean squared successive differences of R-R intervals; LF = low frequency (0.04–0.15 Hz); HF = low frequency (0.15–0.40 Hz); ln = natural logarithmic transformation; DB = deep breathing. *denotes a significant difference (p in case of a significant univariate interaction effect.HR = 心率（heart rate）；SDNN = 正常窦性心搏间期标准差（standard deviation of normal-to-normal beat）；rMSSD = R-R间期逐次差值均方根（root mean squared successive differences of R-R intervals）；LF = 低频（low frequency，0.04–0.15 Hz）；HF = 低频（low frequency，0.15–0.40 Hz）；ln = 自然对数转换（natural logarithmic transformation）；DB = 深呼吸（deep breathing）。*表示存在统计学差异（当单变量交互效应显著时的p值）