The purposes of this study were to develop a low-impact underwater exercise program that can be implemented at water temperatures around 40 degrees C, an environment commonly available in many hot-spring bathing facilities in Japan, and further to verify the effectiveness of the program by experiments.
This program assumes three patterns of bathing, i. e., foot bathing, hip bathing, and chest bathing, considering the designs of bathtubs in such facilities. It also incorporates five categories of underwater exercise, i. e., warming up, toning, flexibility exercise, relaxation, and cooling down, for each pattern of bathing.
The underwater exercise program was tried by ten elderly female subjects (aged 67±5).
The results indicated significant differences in rectal temperature and heart rate from those in plain-water bathing but with little physiologic damage. Therefore, these results suggest that the aged can participat in the newly developed underwater exercise program while they are bathing in hot springs.

Purpose
In recent years, relatively high humidity (100%) and low temperature (40°C) sauna systems called mist saunas have become popular for homes. It is reported that the impact of differing bathing conditions-namely tub bathing and mist sauna bathing-on the circulation of blood in the scalp have been verified in order to clarify the effects of mist sauna on scalp hair: a characteristic of concern to many men.
Method
The testing was performed on 8 healthy men in their twenties (average age: 23.6, average weight: 61.8kg, average height: 166cm). Bathing conditions were mist sauna at 40°C for 10 minutes and full body bathing at 40°C for 10 minutes. Blood circulation in the scalp was observed at the top of their heads using a laser Doppler blood flow meter attached to head gear. At the same time, the skin temperature and local perspiration on their foreheads were measured.
Results and conclusions
Immediately after beginning bathing, the blood flow rose significantly higher during full body bathing than during the mist sauna. No change was observed as full body bathing continued, but during the mist sauna, the blood flow gradually increased until ultimately the blood flow was much higher during the mist sauna than during full body bathing. Based on this result, it is assumed that the increase of scalp blood flow during full body bathing was caused by hydrostatic pressure, and the increase caused by the mist sauna was the result of the heat effects.

In order to investigate the effects of the concentration of chemical components of sea water on thermoregulatory functions, rectal, skin and mean body temperatures were measured continuously before, during total body bathing as well as during recovery period on land.
Eight healthy young men were subjected in the experiment. Their physical characteristics were in average 19.8±1.0yrs in age, 169.2±5.0cm in height, 57.1±3.1kg in weight and 14.0±2.6% in body fat fraction, respectively. Each subject bathed in sea water or in tap water for 15 minutes in the long-sitting position at 38.5°C of water temperature during bathing and took recovery on land for 60 minutes. Water bathing was conducted in individual subject with the concentration of chemical components of sea water at 0, 1, 3.5 and 7%, respectively.
The rectal temperature increased during bathing and decreased gradually during recovery period on land. Statistically significant difference (p<.05) between 0 and 7% of the concentration of sea water was detected in the rectal temperature during bathing and recovery period. The mean skin temperature showed a continuous increase during bathing and showed a rapid decrease during 20 minutes in recovery, and a gradual decrease after then. Statistically significant difference (p<.05) between 0 and 7% of the concentration of sea water was detected in the mean skin temperatures during recovery period. The mean body temperature also showed a continuous increase during bathing and rapid decrease during the first 20 minutes in the recovery period, and decreased gradually thereafter. Statistically significant difference (p<.01) between 0 and 7% of the concentration of sea water was detected in the mean body temperature during bathing and recovery period.

Objectives: Deep seawater (DSW) utilization technology has been developed for the fields of medicine and health, among others. To clarify the health effects of DSW as compared with surface seawater (SSW) or tap water (TW), we investigated the changes of immune cell distribution of the peripheral blood, or subjective judgment scores, after hot water bathing. Methods: Ten healthy young men were immersed for 10 min in DSW, SSW and TW heated to 42°C. Blood samples were collected before bathing, immediately after bathing and 60 min after bathing. Total and differential numbers of leucocytes and lymphocyte subsets (CD3, CD4, CD8, CD19, CD16, and CD56) were examined using an automated hematology analyzer and a flow cytometer, respectively. The subjective judgment scores were obtained by an oral comprehension test. Results: Since the pre-bathing leukocyte count in the TW group was significantly different from those in the DSW and SSW groups, we excluded the findings of TW bathing from consideration. In hot DSW bathing, CD8-lymphocytes increased significantly immediately after bathing (p<0.05), in contrast to hot SSW bathing, in which no significant changes were detected in the lymphocyte subsets. Additionally, there were no significant changes between repeated measurements in the subjective judgment scores, though the score of thermal sensation in SSW bathing showed a significantly higher value immediately after bathing than before bathing (p<0.01). Conclusions: Our findings suggest that increased CD8-lymphocytes in hot DSW bathing may improve human immune function as well as hot springs do, as compared with SSW bathing. Although hot DSW bathing may have the ability to change human immune cell distribution, well-designed studies are needed to clarify the health effects including not only DSW and SSW but also TW.
Bathing self care ; Treated with ; Cells ; Deep ; Antigens, CD8