Regular sauna sessions for six weeks led to significant increases in sympathetic activity, peak nasal inspiratory flow and lung function among people with allergic rhinitis, according to recent research.
The study, “The effect of six weeks of sauna on treatment autonomic nervous system, peak nasal inspiratory flow and lung functions of allergic rhinitis Thai patients,” involved 26 people clinically diagnosed with allergic rhinitis.
According to the study’s authors, allergic rhinitis is an inflammatory respiratory disease. Primary symptoms are sneezing, rhinorrhea, pruritus and congestion. These symptoms are triggered when a person is exposed to certain allergens, such as pollen, mites and dust.
For the study, the patients with allergic rhinitis were randomly assigned to either the control group or sauna group, and all subjects were instructed to refrain from taking any allergic rhinitis medication during the study period. Those assigned to the control group received education on allergic rhinitis and continued with their lives as usual.
Subjects assigned to the sauna group received six five-minute sauna sessions per day, three days a week, for six weeks. Participants rested for 15 minutes before starting their sauna sessions, and rested for five minutes between each five-minute sauna session. The sauna was maintained at a temperature of about 176 degrees to 194 degrees Fahrenheit.
The main outcome measure for this study was heart-rate variability, which was used to assess autonomic nervous system function. One of the secondary outcome measures was peak nasal inspiratory flow, which was used to “detect changes in nasal airflow due to obstructive or inflammatory causes.” The other secondary outcome measure was lung function, which involved subjects breathing into a spirometer to record their forced expiratory volume in one second and forced vital capacity. All outcome measures were assessed at the beginning and again after three and six weeks.
Analyzing the data, the researchers found that subjects in the sauna group experienced significant changes in heart-rate variability. The high frequency (HF) component was significantly lower, and both the low frequency (LF) component and the LF/HF ratio were significantly higher in the sauna group than in the control group.
“The activity of sympathetic function significantly increased after six weeks of repeated sauna treatment, as shown by the evidence of an increase in LF and the LF/HF ratio,” state the study’s authors, “while the lower HF indicated a decrease in parasympathetic activity after sauna treatment.”
Peak nasal inspiratory flow and forced expiratory volume in one second were also significantly higher in the sauna group than in the control group.
Authors: Narupon Kunbootsri, Taweesak Janyacharoen, Preeda Arrayawichanon, Seksun Chainansamit, Jaturat Kanpittaya, Paradee Auvichayapat and Kittisak Sawanyawisuth.
Sources: School of Physical Therapy, Faculty of Associated Medical Science; Improvement of Physical Performance and Quality of Life Research Group; Back, Neck and Other Joint Pain Research Group; Departments of Rehabilitation Medicine; Departments of Otorhinolaryngology; Departments of Radiology; Departments of Physiology; Departments of Medicine, Faculty of Medicine; The Research and Training Center for Enhancing Quality of Life of Working-Age People, all at Khon Kaen University, Khon Kaen, Thailand. Originally published in June 2013 in Asian Pacific Journal of Allergy and Immunology, 31(2), 142-7.