The influence of extreme thermal stress on the physiological and psychological characteristics of young women who sporadically use the sauna: practical implications for the safe use of the sauna.

Background: Many individuals who use the sauna at a temperature of 120°C of higher are not aware of the negative consequences of extreme thermal stress. Despite extensive research into sauna use, the impact of extreme thermal stress on the physiological and psychological characteristics of sauna users have not been examined to date. Aim: The aim was to determine the effect of 20 min sauna sessions with a temperature of 80°C and 120°C on the physiological and psychological characteristics of women who sporadically visit the sauna. Methods: The study was conducted on 22 full-time female university students. Physical activity (PA) levels were evaluated with the Polish short version of the International Physical Activity Questionnaire (IPAQ). Anthropometric characteristics were measured before the first sauna session by the InBody270 body composition analyzer. Physiological parameters, including heart, energy expenditure, physical effort, and blood pressure (systolic blood pressure - SBP, and diastolic blood pressure - DBP), were assessed indirectly using Polar V800 heart rate monitors and the Omron M6 Comfort blood pressure monitor. The participants' wellbeing was assessed with the Profile of Mood States (POMS) questionnaire. The presence of significant correlations between heat exhaustion and heat stress variables and syncope during the second sauna session was examined with the use of classification and regression trees (CRT) and the cross-validation technique. Results: Twenty-minute sauna sessions with a temperature of 80°C and 120°C induced a significant (p < 0.001) decrease in the values of SBP (excluding the temperature of 120°C), DBP, and body mass, as well as a significant increase in HR and forehead temperature. Exposure to a temperature of 80°C led to a significant (p < 0.001) increase in vigor with a simultaneous decrease in tension, depression, anger, fatigue, and confusion. In turn, sauna bathing at a temperature of 120°C had an opposite effect on the above mood parameters. Vomiting and confusion were the main predictors of syncope that occurred in some of the surveyed women. Conclusion: Excessive air temperature can induce symptoms characteristic of heat exhaustion and heat stress nausea, heavy sweating, fast weak or strong HR, high body temperature, and confusion. Therefore, sauna bathing at a temperature of 80°C can be recommended to women who sporadically use the sauna, whereas exposure to a temperature of 120°C is not advised in this group of sauna users. The present findings provide highly valuable inputs for managing wellness and SPA centers.

The Influence of COVID-19 on University Students' Well-Being, Physical Activity, Body Composition, and Strength Endurance.

BACKGROUND: Very few scientific studies have simultaneously evaluated changes in well-being (WB), physical activity (PA), and strength endurance (SE) based on results from before and during the COVID-19 pandemic. AIM: The aim of the study was to assess WB, PA, and SE levels, as well as body composition parameters in university students before and during the pandemic. METHODS: The study included 30 males and 30 females (mean age: 21.7 ± 2.51 and 21.6 ± 2.34 years, respectively). Well-being using the Self-Perception Questionnaire (POMS), PA from the Polish regular version of the International Physical Activity Questionnaire (IPAQ), body composition parameters using the InBody 270 analyzer, and SE based on the results of a 12 min test involving a Concept 2PM-5 rowing ergometer were assessed before and during the pandemic. RESULTS: An assessment of university students' WB revealed a significant increase in variables such as tension, depression, anger, confusion, and a significant decline in vigor (p < 0.05). In both sexes, PA and SE decreased significantly-from 2115.4 to 1822.8 METs-min/week and from 2184.5 to 2035 m, respectively, in males, and from 1793.5 to 1699.8 METs-min/week and from 2021.5 to 1943.8 m, respectively, in females. At the same time, body mass and BMI values increased significantly (p < 0.001) in both females and males. CONCLUSIONS: The COVID-19 pandemic caused a significant decrease in WB, PA and SE levels in young females and males, and led to a significant increase in their body mass and BMI.