Table 5. Multiple regression equation to explain morning mood as a function of morning HRV (n = 123 recordings).

Dependent variable	Independent variable	Non-standardised equation	Standardized coefficients (β)	R2	Sig.
Mood	RRmean SDRR Hfnu	Mood = –1.842 + (0.007 * Rrmean) – (0.026 * SDRR) + (0.034 * Hfnu)	0.515 (Rrmean) −0.381 (SDRR) 0.229 (Hfnu)	0.492*	<0.001

Note:

^*Effect size: f² = 0.968 (large > 0.35); Statistical power: π = 1.00 (for n = 123), three predictors and R² = 0.492.