Physical and mental effects of bathing in bathtub with hot water investigated through randomized intervention study

It has been known that bathing in hot water augments blood flow and stimulates metabolism. However there are just a few reports which showed the effects of bating through interventional study. The purpose of this study is to investigate whether the bating in hot water daily has better effects physically and mentally than taking shower. Subjects were 40 people aged 30 y.o and over and we applied them to bathe in hot water for 2 weeks and to take shower for 2 weeks continuously using cross-over methods from October to November in 2011. Each group was consisted of 20 subjects. We conducted a questionnaire survey in terms of self rated health, smile, pain, condition of skin, stress, and fatigue at the point of 2 weeks and 4 weeks of the study. SF-8 and POMS were also used at the same point. Statistical analysis was performed using paired t-test. Subjects who bath in bathtub with hot water for 2 weeks showed better condition with respect to self rated health, smile and condition of skin than subjects with who take shower for 2 weeks. Stress, fatigue, tension-anxiety, anger-hostility, and depression-dejection were less in subjects who bath in hot water for 2 weeks. This interventional study showed good physical and mental effects of bathing in bathtub. With these results, we recommend to take bath with hot water to promote health condition.