How the sauna affects the endocrine system.
Level 5 - mechanism / opinion, no new human data
Narrative review of endocrine responses to sauna exposure without original empirical data or systematic review methodology.
What was done
The author reviewed literature describing the hormonal and endocrine responses induced by heat exposure during sauna bathing, including changes in catecholamines, fluid balance hormones, pituitary hormones, and stress axes.
What was found
The abstract provides no numerical data, effect sizes, or participant counts. It reports qualitatively that sauna exposure in habituated individuals raises circulating noradrenaline (typically without other catecholamines), increases antidiuretic hormone secretion, activates the renin-angiotensin-aldosterone system, and elevates circulating growth hormone, prolactin, and immunoreactive beta-endorphin. Findings on adrenocorticotropic hormone (ACTH) and cortisol were described as contradictory and dependent on bathing protocols, though cortisol typically does not rise in accustomed Finnish bathers. All reported hormone concentrations normalize within a couple of hours after heat exposure.
Why it matters
It provides a broad overview of how thermal stress affects volume regulation, sympathetic tone, and anterior pituitary signaling, illustrating that acute endocrine responses to heat are transient.
Limits
The abstract reports no sample sizes, specific study designs, sauna protocols (temperature, humidity, duration), or quantitative values. It is a narrative overview, precluding evaluation of underlying study quality, confounding factors, or publication bias.
Cited by
- supports Sauna exposure increases growth hormone significantly more than cold plunges.