Sauna com vapor pesa mais no corpo, aponta estudo finlandês
edited by Gaby Clark, reviewed by Alexander Pol
This article has been reviewed according to Science X's editorial process and policies. Editors have highlighted the following attributes while ensuring the content's credibility:
A newly published Finnish study demonstrates that, in addition to temperature, air humidity is a significant determinant of physiological strain during sauna bathing. As humidity increases, both heart rate and core temperature rise more markedly, indicating a greater cardiovascular and thermoregulatory load.
The University of Jyväskylä and the Finnish Institute of High Performance Sport KIHU conducted this sauna study in collaboration with Harvia.
Finnish saunas are renowned for their high temperatures, but research suggests that the humidity generated by steam also plays a crucial role in physiological responses during sauna bathing. This study investigated how temperature and relative air humidity affect thermoregulatory responses, including changes in heart rate and core temperature, during sauna bathing.
Fifty healthy adults participated in four sauna experiments, during which their heart rates and body temperatures were measured and their perception of heat was assessed.
Heart rate rose by more than 40 beats per minute on average
Sauna bathing caused an intense cardiovascular response. The average heart rate increased from 79 to 121 beats per minute during 10 minutes in the sauna.
According to the results, both temperature and air humidity contributed to the increase in heart rate.
"In addition to temperature, the relative humidity of sauna air affects the thermoregulatory responses. While temperature is still the most significant factor, steam also clearly affects heart rate and core temperature," says Iida Laatikainen-Raussi from the Faculty of Sport and Health Sciences at the University of Jyväskylä.
Humidity impedes the body's cooling process
High relative humidity prevents sweat from evaporating effectively from the skin, reducing the efficiency of the body's main cooling mechanism.
"This increases thermal strain and forces the cardiovascular system to work harder to maintain an adequate body temperature," says Laatikainen-Raussi.
The findings support the notion that the humidity created by steam plays a key role in the effects of the traditional Finnish sauna experience.
Body temperatures rose moderately
On average, subjects' core body temperatures increased from 37.4°C to 37.8°C (99.3°F to 100°F) during the sauna bath, an increase of approximately 0.4°C.
Changes in core body temperature were associated with the temperature and humidity of the sauna; the hotter and more humid the sauna, the higher the core body temperature.
The role of steam in saunas may be underestimated
The researchers suggest that the importance of steam in saunas may have been overlooked in previous studies because variations in humidity were not usually considered in enough detail and different sauna conditions were not adequately measured.
"Future sauna studies and practices should pay more attention to humidity and consider and measure sauna conditions more thoroughly," says Laatikainen-Raussi.
The research is published in the journal Temperature.
Iida Laatikainen-Raussi et al, Temperature and humidity independently influence thermoregulatory responses during Finnish sauna bathing, Temperature (2026). DOI: 10.1080/23328940.2026.2698162
MA in English, copy editor since 2021 with experience in higher education and health content. Dedicated to trustworthy science news. Full profile →
PhD nano-engineering from Delft University. Published researcher and journal reviewer. Brings scientific insight to content standards. Full profile →
Acompanhe a Recifes.net
Gostou desta leitura? Siga a Recifes nas redes e receba as proximas pautas no WhatsApp.
Matéria produzida com curadoria editorial assistida por IA, a partir de pauta de medicalxpress.com.
