Table 2. Effect sizes (Cohen′s d) calculated by comparing water immersion strategies versus CTRL for each of the heart rate variability index and moment.

	ln rMSSD	mRR	SD1	SD2
WI
CWI	0.54	0.60	0.54	0.08
TWI	0.41	0.33	0.41	0.91
HWI	1.68	1.23	1.68	1.81
POST-WI
CWI	1.83	1.38	1.82	1.24
TWI	0.71	0.45	0.71	0.56
HWI	0.66	1.11	0.66	0.69
POST-REC
CWI	0.15	0.24	0.15	0.21
TWI	0.11	0.38	0.11	0.12
HWI	0.13	0.91	0.13	0.19

Effect sizes <0.2 ‘trivial’; 0.2–0.5 ‘small’; 0.5–0.8 ‘moderate’ and >0.8 ‘large’.

CTRL is control (recovery at room temperature), CWI is cold water immersion (recovery in water at 15°C), TWI is temperate water immersion (recovery in water at 28°C), HWI is hot water immersion (recovery in water at 38°C). WI is the response during water immersion, POST-WI is the response after water immersion, POST-REC is the response after 4 hours of recovery. mRR: mean R-R intervals; ln rMSSD: normal logarithm of the square root of the mean of the sum of the squares of differences between adjacent normal R–R intervals; SD1: instantaneous beat-to-beat variability; SD2: continuous beat-to-beat variability.