Tracking of menstrual cycles and prediction of the fertile window via measurements of basal body temperature and heart rate as well as machine-learning algorithms

Table 2 The relationship between menstrual cycle and physiological parameters in the regular group

Physiological parameter	BBT^{a, b}	HR^{a, c}	Ln(SDNN^{a, d})	Ln(LF/HF ratio^{a, e})
Intercept	36.63 (0.02)	62.50 (0.54)	4.80 (0.02)	-0.55 (0.02)
Cycle phase
Menstrual	Reference	Reference	Reference	Reference
Follicular	-0.03 (0.01)^f	0.23 (0.13)	-0.00 (0.01)	0.02 (0.01)
Fertile	0.01 (0.01)	0.84 (0.12)^f	-0.04 (0.01)^f	0.05 (0.01)^f
Luteal	0.19 (0.01)^f	2.69 (0.11)^f	-0.10 (0.01)^f	0.05 (0.01)^f
Follicular	Reference	Reference	Reference	Reference
Fertile	0.04 (0.01)^f	0.61 (0.13)^f	-0.04 (0.01)^f	0.03 (0.01)^f
Fertile	Reference	Reference	Reference	Reference
Luteal	0.18 (0.01)^f	1.84 (0.11)^f	-0.06 (0.01)^f	0.00 (0.01)

^aUnstandardized beta-coefficient values (standard error) reported with adjusted p values using a Bonferroni correction
^bBBT, basal body temperature
^cHR, heart rate
^dSDNN, standard deviation of normal-to-normal intervals
^eLF/HF ratio, low frequency /high frequency ratio
^fP < 0.001

ISSN: 1477-7827