Table 3. Autonomic, endocrine, and subjective recovery outcomes. Outcome Thermoneutral shower control T0 Thermoneutral shower control T1 Thermoneutral shower control T2 Contrast heat-cold T0 Contrast heat-cold T1 Contrast heat-cold T2 Between-group ΔΔ (T1-T0 / T2-T0), effect size, p-value TQR (a.u.) 13.4 ± 0.5 15.9 ± 0.5 13.5 ± 0.5 13.1 ± 1.0 16.2 ± 0.9 13.3 ± 0.5 ΔΔ 0.61 (95% CI 0.27 to 0.95), p < 0.001; g 0.80. ΔΔ 0.12 (95% CI -0.37 to 0.62), p = 0.622; g 0.16. Salivary cortisol (nmol/L) 16.0 ± 1.5 15.2 ± 1.4 16.1 ± 1.5 16.0 ± 1.7 15.9 ± 1.4 16.0 ± 1.5 RRR 1.05 (95% CI 0.99 to 1.11), p = 0.132; g 0.43. RRR 1.00 (95% CI 0.93 to 1.07), p = 0.962; g -0.02. Resting HR (bpm) 61 ± 3 61 ± 3 61 ± 3 60 ± 3 58 ± 3 60 ± 3 ΔΔ -2.10 (95% CI -2.24 to -1.96), p < 0.001; g -0.65. ΔΔ 0.01 (95% CI -0.14 to 0.15), p = 0.934; g 0.00. lnRMSSD (log units) 4.13 ± 0.15 4.13 ± 0.16 4.13 ± 0.15 4.10 ± 0.17 4.23 ± 0.17 4.10 ± 0.18 ΔΔ 0.123 (95% CI 0.108 to 0.137), p < 0.001; g 0.74. ΔΔ -0.002 (95% CI -0.016 to 0.012), p = 0.776; g -0.01. RMSSD (ms) 62.9 ± 9.8 63.1 ± 10.1 62.9 ± 9.9 61.5 ± 11.0 69.7 ± 12.3 61.3 ± 10.9 ΔΔ 7.97 (95% CI 6.91 to 9.02), p < 0.001; g 0.75. ΔΔ -0.12 (95% CI -1.02 to 0.77), p = 0.783; g -0.01. SDNN (ms) 88.1 ± 13.3 89.5 ± 14.0 85.4 ± 13.9 86.7 ± 19.0 98.6 ± 18.1 85.9 ± 16.2 ΔΔ 10.48 (95% CI 6.47 to 14.49), p < 0.001; g 0.63. ΔΔ 1.87 (95% CI -1.90 to 5.64), p = 0.325; g 0.11. Values are mean ± SD. TQR, Total Quality Recovery; HR, heart rate; lnRMSSD, natural logarithm of the root mean square of successive differences between normal-to-normal RR intervals; RMSSD, root mean square of successive differences between normal-to-normal RR intervals; SDNN, standard deviation of normal-to-normal RR intervals; ΔΔ denotes the between-group difference in change from baseline (contrast minus control). Effect sizes are Hedges g for pretest-posttest control designs. RRR denotes a ratio of ratios for the log-modeled cortisol outcome.