Suggested Effects of Warm Deep Sea Bathing on Daylight Sleep and Relaxation in Night Shift Workers

Abstract

In order to investigate the effects of deep sea water bathing on relaxation and daylight sleep in night shift workers, electroencephalography, circulatory and cardiac autonomic functionings, visual evoked potential, biochemical markers in urine and saliva, core body temperature, sleep questionnaires, and mood state questionnaires were evaluated in nine subjects to compare with other three kinds of bathing including sham (no water), tap water and surface sea water. Deep sea water bathing showed better subjective sleep latency for sleep questionnaire (p<0.1) and significantly better vigor status for mood questionnaire (p<0.01) between four kinds of bathing. With regard to the objective data, despite the biggest increase in temperature of eardrum in deep sea water bathing, the highest sleep efficiency and the shortest wake period during sleep in electroencephalography did not reach to the significant level.