A hot topic for health: Results of the Global Sauna Survey

https://doi.org/10.1016/j.ctim.2019.03.012Get rights and content

Highlights

  • This is the first study to investigate the health habits of the global sauna community.

  • Relaxation/stress reduction was the most cited motivation to use a sauna.

  • Most sauna bathers cited improvements in sleep lasting 1–2 nights after using a sauna.

  • Sauna users 5–15 times monthly had comparatively higher mental well-being scores.

  • Most adverse reactions to sauna bathing were mild reports of dizziness and dehydration.

  • Many report sauna bathing to ‘detox’, not yet well-understood by the research community.

  • Few report sauna bathing for cardiovascular benefits, which is supported by research.

  • Further studies and greater education around sauna as a wellness intervention are needed.

Abstract

Objective

Sauna-bathing is an ancient tradition that is gaining popularity across the world as a wellness tool. There is a growing body of medical evidence supporting the role of saunas, or whole-body thermotherapy, as a form of treatment for a range of health issues. However, the demographics, motivations and experiences of current sauna bathers have not yet been explored on a global scale. This study is designed to explore these themes.

Design

An online 71-item questionnaire compiling information on the individual characteristics, sauna-related habits and perceived health and wellness experiences of regular sauna bathers was conducted from October 2016 to October 2017. The validated ‘SF-12’ quality of life scoring tool was incorporated into the questionnaire to measure physical and mental indicators of well-being.

Results

Of 572 logins recorded, 482 valid responses were generated. Both men (51.3%) and women (48.7%) were represented, and respondents were predominantly well-educated (81.8%), non-smoking (90.6%), regularly-exercising (78.8%) individuals of normal-to-overweight status (87.1%) who sauna-bathed approximately 1–2 times per week. The key reasons indicated by respondents for sauna-bathing included relaxation/stress reduction, pain relief and socializing. Nearly a third of respondents reported medical conditions and of this subset, those with back/musculoskeletal pain and mental issues cited the greatest improvements in their conditions with sauna-bathing. Of all respondents, 83.5% reported sleep benefits after sauna use. Analysis of well-being scores after stratifying respondents into three groups by sauna-bathing frequency (group I: <5 times per month; group II: 5–15 times per month; group III: >15 times per month) revealed group II respondents had slightly higher mental well-being scores (Kruskal–Wallis testing: H = 6.603 > ꭔ2 of 5.991, p = 0.0368, df = 2 with post hoc analysis using Mann–Whitney U test: p = 0.016) as compared to respondents who were sauna-bathing less frequently (group I). No respective differences were detected between the physical well-being scores of any of the three groups. Adverse reactions to sauna-bathing were recorded as mostly minor (93.1%), including primarily symptoms of dizziness, dehydration and headache. However, there were two reports (0.3%) of chest pain and eye irritation requiring hospitalization.

Conclusions

This cross-sectional study documents that sauna-bathing participants, particularly those from Finland, Australia and the United States, are motivated to use saunas predominantly for relaxation, reporting health benefits especially around mental well-being and sleep, with relatively few adverse effects. While these results reinforce some of the known health benefits of sauna bathing, they indicate that further research and better dissemination of existing evidence is needed to fully develop the sauna's potential as a therapeutic intervention.

Introduction

Sauna bathing in various forms has been used for centuries for health, hygiene, social and spiritual purposes and is currently undergoing a worldwide resurgence, largely as a result of an increasing individual and public health focus on wellness.a 1, 2 Recent long-term observational studies emerging from Finland demonstrate strong associations between frequent sauna bathing and a reduced incidence of cardiovascular events,3 cerebrovascular events (i.e. strokes),4 respiratory diseases (i.e. pneumonia,5 asthma and chronic obstructive pulmonary disease6), dementia7 as well as lowered markers of systemic inflammation8 and higher quality of life.9 These findings suggest sauna bathing has preventive health benefits comparable in many respects to regular exercise.10, 11, 12

In addition to epidemiological studies, specific medical interest in sauna bathing or ‘whole body thermotherapy’ is ‘heating up’, as demonstrated by an increase in citations and reviews of health-related studies involving various types of sauna interventions.13, 14 The clinical use of dry sauna bathing (i.e. traditional Finnish style and/or infrared, etc.) has been documented to have beneficial health effects and improve cardiovascular, respiratory, immunological, metabolic and athletic performance.11, 13, 15, 16, 17, 18, 19, 20, 21 The precise drivers of these effects remain unclear. While recent studies suggest the beneficial health effects of sauna bathing may be due to endothelial-dependent vasodilatation metabolic and immune pathways, more research is needed.10, 11, 15, 22, 23, 24, 25 Routine sauna bathing has been reported to be relatively safe provided bathers use common sense and avoid concurrent alcohol consumption.13, 26, 27, 28, 29 Of note, there is small-scale evidence to suggest reversible impairment of male spermatogenesis with regular sauna bathing, however further study is required to validate this evidence.13, 30

While there is growing interest in the health impacts of sauna bathing and a multitude of anecdotal reports on sauna-related blogs and websites, there is comparatively little data in the English-speaking scientific literature on the general characteristics and motivations of people who already use the sauna regularly, particularly on a global basis. There are various studies that have surveyed the sauna habits of distinct populations (i.e. Finnish octogenarian men9 and MSM – men who have sex with men31, 32, 33), however the health-related outcomes of these studies are not generalizable to the public (e.g. women). Thus, although there is mounting medical evidence suggesting saunas should play a greater role as a lifestyle wellness/therapeutic tool, there is an ongoing need to document health information around existing sauna use, as is presented in this study.

We aimed to explore the current demographics, motivations, health and wellness experiences of sauna bathers worldwide via an online questionnaire.

Section snippets

Design and objectives

This study used a cross-sectional, descriptive survey to document the following information about sauna bathers:

  • Demographics (i.e. age, gender, education and country of residence)

  • Personal health and lifestyle information (i.e. general state of health, quality of life measures, medical conditions and severity, diet/exercise habits and other lifestyle habits)

  • Motivations for sauna activities (intentions and importance)

  • Sauna characteristics and associated habits (i.e. frequency, timing and types of

Results

A total of 572 logins were recorded but after accounting for duplicate entries (n = 4), entries with denied consent (n = 2) and entries with insufficient data (n = 84), there were 482 valid responses generated. A valid response entailed completion of at least one additional question, aside from the introductory question providing informed consent. A total of 378 respondents (78.4%, n = 378/482) responded to every question in the questionnaire.

Summary of findings

To our knowledge, this is the first study to investigate the health-related habits of the global sauna community, to include participants from multiple countries and continents and to provide a balanced representation of women and men. Our results indicate respondents were predominantly well-educated, non-smoking, regularly-exercising individuals of normal-to-overweight status who generally reported overall good health. ‘Relaxation/stress reduction’ was the most common motivation for sauna

Conclusions

Sauna bathing is currently used by a wide range of ages and nationalities. This study demonstrated that sauna use has perceived health benefits that vary from generalized effects such as relaxation, stress relief, invigoration, and socializing to more specific effects such as aiding circulation, improving sleep, improving mental health, enhancing ‘detoxification’, and relieving back/musculoskeletal pain. The few reported incidences of adverse reactions to sauna bathing were mild and included

Authors’ contributions

Marc Cohen and Joy Hussain conceived the strategy to use a cross-sectional study design to better understand health behaviors around sauna-bathing. Joy Hussain designed, conducted and completed analysis of the study as part of her PhD project and wrote the first draft of the manuscript. MC and RG supervised this project as part of JH's PhD candidature. All authors contributed to the writing of the subsequent drafts, and reviewed, edited, and approved the final manuscript.

Funding

Dr Joy Hussain has received a PhD scholarship from the Jacka Foundation and RMIT University in Australia.

Financial disclosure

None declared.

Conflict of interests

None declared.

Acknowledgements

The authors would like to sincerely thank the worldwide respondents of this survey for their motivation and enthusiasm completing such a detailed survey. The counsel and advice of Dr Jack Tsonis of Western Sydney University and the Australian Sweat Bathing Association (ASBA) has been much appreciated. We also wish to thank Ambassador Lars Backström and Deputy Head Antti Niemelä of the Finnish Embassy in Canberra, Australia as well as CEO Charles Davidson of Peninsula Hot Springs, London-based

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