TABLE 1.

Time and frequency heart rate variability indicators.

	Pre dive mean	SE	Post dive mean	SE	p-value
Low frequency (ms2)	451.56	44.31	594.11	71.64	0.002
Total low frequencies (ms2)	608.72	55.42	809.37	85.42	0.001
High frequency (ms2)	69.24	8.32	106.53	18.94	0.001
LF/HF ratio	8.50	0.82	8.21	0.74	0.280
LF as ratio of total variability	0.23	0.02	0.23	0.02	0.461
Total low frequencies (n.u.)	0.90	0.01	0.89	0.01	0.203
HF as ratio of total variability	0.03	0.002	0.04	0.00	0.144
RMSSD	19.95	1.02	25.36	1.90	0.000
SDNN (ms)	43.35	1.57	48.40	2.60	0.002