Introduction: Some students take showers instead of baths for economic reasons or because they dislike cleaning the bathtub. The purpose of this study was to examine the effect of bathing routines on students’ working efficiency. Subjects: Seventeen (six male and 11 female) healthy young students (19.6 ± 0.7 years old, mean ± SD) who habitually took showers instead of baths participated in this study. Informed consent was obtained from all the subjects and the study was approved by the Ethics Committee of Kumamoto Health Science University. Method: Subjects were randomly assigned into two groups. The subjects in the first group (bathtub bathing [BB]) were immersed to the supraclavicular level in their home bathtub and instructed to rest for 10 minutes with the temperature regulated at 41°C. The subjects of the second group (whole-body warming after BB [BBW]) followed the same bathing protocol and then rested in a sleeping bag and sheet for 30 minutes to keep their bodies warm. Each period was carried out over 2 weeks in a cross-over design. Washout periods were 2 weeks long. The evaluation items of this study included the obstructive sleep apnea (OSA) sleep inventory MA version (OSA-MA), a questionnaire containing a visual analog scale (VAS) to judge the subjective bathing effect, profile of mood states, salivary stress marker (α-amylase), and the Purdue Pegboard test. These tests were evaluated before and after the BB sessions, BBW sessions, and washout interval for a total of four times in a 6-week period. Result: Participants tended to report a better sleep feeling on the OSA-MA after the BB or BBW sessions than after showering. There were significantly better changes in both the BB and BBW in the VAS for bathing effect in terms of “Sense of deep sleep,” “Body fatigue,” “Light feeling of the body” than after a shower. The mean α-amylase value in the saliva of the BBW group participants was significantly lower than that after showering. The mean Purdue Pegboard test scores of both the BB and BBW sessions were significantly higher than that after the shower. Discussion: Sleep quality seemed to be more improved after BB or BBW than after showering, perhaps due to reduced stress. Work efficiency also increased in the BB and BBW groups.

Objective: The purpose of this study was to examine the effects of bathtub bathing （BB） on sleep and working efficiency of healthy young adult students. Furthermore, the effects of BB and prolonged increased body temperature from the use of insulating sheets and sleeping bags after BB （warming after BB: BBW） on sleep and working efficiency were investigated. Subjects: Eighteen （six males, 12 females） healthy young students （19.6±0.7 years old, mean±SD） who habitually took showers instead of baths participated in this study. Informed consent was obtained from all of the subjects, and the study was approved by the Ethics Committee of Kumamoto Health Science University. Methods: Subjects were randomly assigned to two groups （n＝9 in each group）. The subjects in the BB group were immersed in their home bathtub to the supraclavicular level and instructed to rest for 10 min with the temperature regulated at 41°C. The subjects in the BBW group followed the same bathing protocol, and they then rested in a sleeping bag and sheet for 30 min in order to keep their bodies warm. The length of each study period was 2 weeks in a crossover design. After the 2-week-long washout periods, the subject groups were switched. The subjects were evaluated with the Oguri-Shirakawa-Azumi sleep inventory, MA version （OSA-MA）, which utilizes a visual analog scale （VAS） with which subjects rate their sleep when they wake up, and Purdue Pegboard Assembly test. These tests were employed before and after the BB and BBW sessions, resulting in four testing periods in the 6-week period. Results: Sleep rating on the OSA-MA was no significant difference in both the BB and BBW groups compared to ratings recorded after showering. The subjects in the BB and BBW groups had significantly increased VAS ratings for “Feeling of sound sleep,” “Refreshing,” and “Lightness of the body” compared to the ratings after showering. The mean Purdue Pegboard test scores of the subjects in both the BB and BBW groups were significantly higher than those recorded after showering. Discussion: Changing bathing style from shower to BB or BBW improved the working efficiency of students on the Purdue pegboard test. BB and BBW resulted in soothing effects owing to improvements in the subjects’ quality of sleep.

Objective: The purpose of this study was to clarify the chronic effects of bathtub bathing (BB), whole body warming after bathtub bathing (BBW), and bathtub bathing with herbal extracts (BBH) on the mental condition of healthy young persons. Subjects and Methods: Experiment 1: Eighteen (6 male and 12 female; age: 19.6±0.7 years, mean ± SD) healthy young persons who were taking a shower habitually but not bathtub bathing participated in this study.   From November 2012 to December 2012, subjects were randomly assigned into two groups (each 3 male, 6 female): those who had BB or 30-min BBW 14 times for 14 consecutive nights during a 2-week period. After a 2-week washout period, subjects were asked to switch their bathing conditions (a cross-over design). Experiment 2: Twenty (8 male and 12 female; age: 21.3±1.6 years, mean ± SD) healthy young persons who were taking a shower habitually but not bathtub bathing participated in this study.   From October 2013 to November 2013, subejects (4male and 6 female) were randomly assigned to undergo BB or BBH.   The herbal extract contained Dong dang gui (Japanese Angelica Root), Chimpi (Citrus Unshiu peel), Chamomilla recutita, and ginger extracts.   After a 2-week washout period, subjects were asked switch to the other bathing condition (a cross-over design).   All participants provided informed consent for participation in these studies, and these studies were approved by the Ethics Committee of the Kumamoto Health Science University.   The subjects immersed their bodies up to the supraclavian for 10 min, in tap water adjusted to a temperature of 41 °C in their bathtub at home. The subjects’ mental conditions were assessed using Profile of Mood States short version questionnaire.   The differences in the effect of BB and BBW, as well as those of BB and BBH on the subjects’ mental conditions and their mental conditions pre-BB and post-BB, pre-BBW and post-BBW, pre-BBH and post-BBH were analyzed using Wilcoxon’s signed-rank sum test. Results: The points for depression-dejection, fatigue, and confusion in those who had BBH significantly converged to the median average (50 points) compared to the points in those who had BB.   The points for anger-hostility before BBW and BBH significantly converged to the median average (50 points) after BBW and BBH, and there were no significant differences in points before and after BB. Conclusions: The subjects’ anger-hostility was influenced by body warming in BBW and the vasodilatory components of the herbal extracts.   The subjects’ depression-dejection and fatigue was influenced by the fragrance and color of herbal extracts.