Table 2.

Spearman’s rank-order correlation between running time and heart rate (HR), and parameters of the HR variability

		Running time	Age	BMI	HR—U1	SDNN U1
Running time	Correlation coefficient	1000	0.388	0.309	0.258	−0.044
	Sig. (2-sided)	.	0.067	0.151	0.234	0.846
Age	Correlation coefficient	0.388	1.000	−0.211	0.05	−0.409
	Sig. (2-sided)	0.067	.	0.281	0.801	0.038
BMI	Correlation coefficient	0.309	−0.211	1.000	0.421	0.041
	Sig. (2-sided)	0.151	0.281	.	0.026	0.841
HR U1	Correlation coefficient	0.258	0.05	0.421	1.000	−0.430
	Sig. (2-sided)	0.234	0.801	0.026	.	0.029
SDNN U1	Correlation coefficient	−0.44	−0.409	0.041	−0.430	1.000
	Sig. (2-sided)	0.846	0.038	0.841	0.029	.

BMI, body mass index; SDNN, the SD of all normal RR intervals; Sig., significance level; U1, investigation 7 days before the run.