TABLE 5.

Visualization of the spectral heart rate variability (HRV) features that yielded statistically significant results due to the artificial gravity (AG) training.

Spectral property	F-value	p-Value	Effect size
Class	3.500	0.002	0.143
Fmax	4.467	0.000	0.175
VHF	4.492	0.000	0.176
	Pairwise comparisons	Mean difference	p-Value	CI (95%)
Class	Standing 5 min vs 1.5g	−0.378	0.035	(−0.740, −0.015)
Fmax	Standing 5 min vs 0.5g	−0.118	0.026	(−0.228, −0.008)
Fmax	Standing 5 min vs 0.7g	−0.104	0.005	(−0.185, −0.023)
Fmax	Standing 5 min vs 1.2g	−0.095	0.024	(−0.183, −0.008)
Fmax	Standing 5 min vs 1.5g	−0.083	0.011	(−0.154, −0.012)
VHF	Standing 5 min vs 0.7g	−0.108	0.019	(−0.206, −0.011)
VHF	0.7 vs 2g	0.105	0.012	(0.015, 0.195)

These features were the maximum frequency (Fmax) of the Lomb–Scargle periodogram, its corresponding frequency range (Class) and the very high frequency (VHF) range.