The aim of this study was to investigate the effect of low intensity stretch training on sleep. We examined changes in Sleep Onset Latency, Sleep Efficiency, Total Sleep Time, and Wake After Sleep Onset in response to exercise training in middle-aged female workers. Forty subjects without any medication or illness affecting sleep took part in the study. The subjects were randomly allocated to either a training intervention group（ n=20, 50.7± 7.0 yr）or a nontraining control group（n=20, 51.2±7.9 yr）. The exercise program consisted of stretching according to yoga techniques and poses. Subjects attended a seminar once a week during the three-week intervention to learn the proper stretching techniques. The intervention group was instructed to perform the program immediately before bedtime every day. Sleep/wake assessments were evaluated using an activity measurement apparatus （Actiwatch）during the 1-week pre- and post-intervention periods. The rate of compliance with the program was 75.8%. The intervention group showed a significantly greater decrease in Sleep Onset Latency than the control group at the end of the intervention（－2.7 minutes vs. －10.2 minutes, P=0.022）on work days. No significant mean inter-group differences were observed on non-work days. These results suggest that the program is a practical method for use in daily life, and is effective in promoting greater improvements in sleep-related problems by shortening Sleep Onset Latency in middle-aged female workers.
