Table 2. Repeated measures correlations between different heart rate variability and direct current potential variables with competitive performance for four elite international long jump athletes in a 16-week period that included the qualification for and competition at the 2016 Olympic Games.
r [95% CI] p
LnRMSSD -0.46 [-0.76, -0.01] 0.03*
LnRMSSD %CV 0.41 [0.00, 0.71] 0.05*
R-R interval -0.17 [-0.58, 0.31] 0.46
LnRMSSD:RR -0.28 [-0.65, 0.21] 0.23
LnRMSSD-7 -0.55 [-0.79, -0.17] <0.01**
LnRMSSD:RR-7 -0.01 [-0.43, 0.42] 0.97
DC 0.09 [-0.40, 0.55] 0.69
DC-7 0.26 [-0.22, 0.64] 0.26
* - p <0.05.
LnRMSSD - natural logarithm of the square of the mean sum of the squared differences between R-R intervals, LnRMSSD %CV - LnRMSSD coefficient of variation, LnRMSSD:RR - LnRMSSD to R-R interval ratio, LnRMSSD-7 – LnRMSSD averaged over 7 days, LnRMSSD:RR-7 - LnRMSSD:RR averaged over 7 days, DC – direct current potential, DC-7 – direct current potential averaged over 7 days, r – correlation coefficient; CI – confidence interval,