Recovery from sauna bathing favorably modulates cardiac autonomic nervous system. (August 2019)

• Record Type: Journal Article
• Authors: Laukkanen, Tanjaniina; Lipponen, Jukka; Kunutsor, Setor K.; Zaccardi, Francesco; Araújo, Claudio Gil S.; Mäkikallio, Timo H.; Khan, Hassan; Willeit, Peter; Lee, Earric; Poikonen, Sanna; Tarvainen, Mika; Laukkanen, Jari A.
• Is Part Of: Complementary therapies in medicine. Volume 45(2019)
• Page Start: 190
• Page End: 197
• Publication Date: 2019-08
• Subjects: Sauna bathing -- Heat therapy -- Heart rate variability -- Cardiovascular response; Alternative medicine -- Periodicals; Complementary Therapies -- Periodicals; Médecines parallèles -- Périodiques; Thérapeutique -- Périodiques; Alternative medicine; Electronic journals; Periodicals; 615.5
• DOI: 10.1016/j.ctim.2019.06.011
• Languages: English
• ISSNs: 0965-2299

Abstract

Highlights: Sauna bathing, an activity that has been mainly used for pleasure and relaxation, is also becoming popular in many other populations. Emerging Sauna bathing may be linked to several health benefits, including reduction in the risk of cardiovascular and neurocognitive diseases. It has been postulated that regular sauna bathing may improve cardiovascular function via changes in endothelium-dependent dilatation, arterial stiffness, the autonomic nervous system. The study showed that a single sauna exposure leads to significant changes in cardiac autonomic nervous balance as indicated by modulation of heart rate variability. Abstract: Objective: Sauna bathing is becoming a common activity in many countries and it has been linked to favorable health outcomes. However, there is limited data on the heart rate (HR) and heart rate variability (HRV) responses to an acute sauna exposure. Design: We conducted a single-group, longitudinal study utilizing a pre-post design to examine acute effects of sauna bathing on the autonomic nervous system as reflected by HRV. A total of 93 participants (mean [SD] age: 52.0 [8.8] years, 53.8% males) with cardiovascular risk factors were exposed to a single sauna session (duration: 30 min; temperature: 73 °C; humidity: 10–20%) and data on HRV variables were collected before, during and after sauna. Results: Time and frequency-domain HRV variables were significantly modified (p < 0.001) by the single sauna session, with most of HRV variables tending to return near to baseline values after 30 min recovery. Resting HR was lower at the end of recovery (68/min) compared to pre-sauna (77/min). A sauna session transiently diminished the vagal component, whereas the cooling down period after sauna decreased low frequency power (p < 0.001) and increased high frequency power in HRV (p < 0.001), favorably modulating the autonomic nervous system balance. Conclusions: This study demonstrates that a session of sauna bathing induces an increase in HR. During the cooling down period from sauna bathing, HRV increased which indicates the dominant role of parasympathetic activity and decreased sympathetic activity of cardiac autonomic nervous system. Future randomized controlled studies are needed to show if HR and HRV changes underpins the long-term cardiovascular effects induced by regular sauna bathing.