I see the term “healthspan” coming into vogue lately. It is a big improvement upon “lifespan”, the two being radically different for much of the population. A simple change in terminology is a powerful tool for persuasion and thus progress, and the term feels sticky to me.
Sauna use, sometimes referred to as "sauna bathing," is characterized by short-term passive exposure to high temperatures, typically ranging from 45 °C to 100 °C (113 °F to 212 °F), depending on modality.
This exposure elicits mild hyperthermia, inducing a thermoregulatory response involving neuroendocrine, cardiovascular, and cytoprotective mechanisms that work in a synergistic fashion in an attempt to maintain homeostasis.
Repeated sauna use acclimates the body to heat and optimizes the body's response to future exposures, likely due to the biological phenomenon known as hormesis. In recent decades, sauna bathing has emerged as a probable means to extend healthspan, based on compelling data from observational, interventional, and mechanistic studies
Of particular interest are the findings from large, prospective, population-based cohort studies of health outcomes among sauna users that identified strong dose-dependent links between sauna use and reduced morbidity and mortality. This review presents an overview of sauna practices; elucidates the body's physiological response to heat stress and the molecular mechanisms that drive the response; enumerates the myriad health benefits associated with sauna use; and describes sauna use concerns.
The evolving field of aging research has undergone dramatic shifts in recent decades, as the prevailing view of aging as a non-modifiable inevitability has given way to the possibilities of extending lifespan and, even more promising, healthspan. A widely accepted definition of healthspan is the period of one's life spent in good health, free from the chronic diseases and disabilities that commonly accompany aging (Kaeberlein, 2018). Healthspan extension compresses the time spent in ill health, shifting it to one's later years. Sauna use has emerged as a probable means to increase lifespan and extend healthspan.
• Sauna use mimics physiological and protective responses induced during exercise.
• Repeated sauna use optimizes stress responses via hormesis and heat shock proteins.
• Sauna use appears to reduce morbidity and mortality in a dose-dependent manner.
• Frequent sauna use may protect against cardiovascular and neurodegenerative disease.
• Sauna use provides a means of preserving muscle mass and countering sarcopenia.
WIND: more research on this is welcome, since correlation is not causation. However, when something is dose-dependent, that gets my attention, since that suggests causal.
I wish I had access to a sauna, but it is economically impractical for me (eg paying for it, or even constructing/heating one). Does baking in the sun count?
I do know from past training (cycling) that the body indeed does adapter to heat stress quite remarkably. So I am very open to the idea that sauna may induce plenty of physiological adaptations.