Some endocrine responses to sauna, shower and ice water immersion.
Level 3 - non-randomized controlled study
Non-randomized crossover physiological comparative study in a small cohort
What was done
Nine male winter swimmers were exposed to four distinct protocols followed by recumbent recovery: (A) sauna and ice-water immersion; (B) sauna and 15°C shower; (C) sauna and room temperature; and (D) head-out ice-water immersion and room temperature. Concentrations of plasma ACTH, serum cortisol, serum melatonin, plasma norepinephrine, and plasma epinephrine were measured at baseline, post-exposure, and post-recovery.
What was found
Melatonin concentrations did not change. Post-exposure norepinephrine levels increased significantly from baseline across exposures (P < 0.05). Post-exposure epinephrine showed a tendency to elevate and nearly doubled (P < 0.05) in experiment A (sauna and ice-water immersion). ACTH and cortisol showed slight post-exposure increases. Exact absolute concentrations and variance metrics were not reported in the abstract.
Why it matters
It characterizes acute sympathoadrenal and pituitary-adrenocortical responses to extreme thermal contrast protocols in cold-habituated individuals.
Limits
The sample size is very small (n = 9) and restricted to male winter swimmers, limiting generalizability to women or non-adapted populations. Randomization of protocol order is not stated, and the abstract omits baseline and post-exposure numerical values.
Cited by
- context Cold water immersion in a cold plunge reduces cortisol levels while increasing adrenaline, dopamine, and norepinephrine.