address: Hideki Tanaka, Department of Clinical Psychology, Faculty of Human and Social Environment, Hiroshima International University, 555-36 Gakuendai, Kurose, Kamogun, Hiroshima 724-0695, Japan. Email: firstname.lastname@example.org
Abstract The effects of short naps and exercise on the sleep quality and mental health of elderly people was investigated. ‘Interventions’ by short naps after lunch and exercise of moderate intensity in the evening were carried out for 4 weeks. After the ‘intervention’, awake time after sleep onset decreased significantly and sleep efficiency increased significantly, demonstrating that sleep quality had improved. Also, the frequency of nodding in the evening decreased significantly. These results demonstrate that proper awakening maintenance in the evening was effective in improving sleep quality. After the ‘intervention’, mental health and volition and physical health had also improved with improving sleep quality.
Sleep disorders are among the most common difficulties facing the elderly whose primary goal is to maintain a healthy and independent lifestyle. We have reported previously that a short nap (30 min between 13.00 and 15.00 hours) and moderate exercise, such as walking in the evening, are important in the maintenance and improvement of sleep quality.1 The present study examined the effects of a short nap and evening exercise of moderate intensity on the sleep quality and mental health of elderly subjects.
The subjects comprised 11 elderly people (73.8 ± 5.4 years) who gave informed consent for their participation. ‘Intervention’ by a short nap after lunch (30 min between 13.00 and 15.00 hours) and evening exercise of moderate intensity, including stretching and flexibility (30 min from 17.00 hours), was carried out for 4 weeks in winter. All subjects were able to lead a normal life at home, and screening tests before the ‘intervention’ were used to exclude those who experienced sleep problem due to illness. The subjects’ physical activities were recorded using actigraphs for 1 week before and postintervention. Actigraph data were analysed to determine ‘sleep’ and ‘wake’ periods by applying a Cole’s validated algorithm2 to the portions of the records identified as sleep periods by the combination of sleep logs. Mental health was assessed using the General Health Questionnaire (GHQ).3 Furthermore, after the intervention, a questionnaire mainly enquiring about subjects’ volition and physical health was performed.
After the ‘intervention’ (Fig. 1), sleep efficiency increased significantly, demonstrating that sleep quality had improved. Furthermore, nodding in the evening decreased significantly after the ‘intervention’. Subjects’ GHQ scores also decreased significantly, showing that their mental health had also improved. After the ‘intervention’, many of the participants answered that volition and physical health had also improved (volition 63.6%; physical health 90.9% of all subjects).
The study’s results demonstrated that proper awakening maintenance during the evening was effective in improving sleep quality. Until recently, it has been considered that taking a nap has a negative effect on the quality of nocturnal sleep. However, a short nap of 30 min between 13.00 and 15.00 hours has little quantitative effect on nocturnal sleep. Moreover, a short nap is effective in improving the recovery of attention, concentration and brain function.4 The present study’s results reconfirm that the habit of taking a short nap is effective in maintaining sleep quality,1,4 and indicate that napping is an effective way for the elderly to maintain their quality of sleep. The body temperature phase of the elderly is advanced by 2–3 h compared with that of young people.5 Moreover, the existence of a ‘forbidden zone’ has been demonstrated.5 This ‘forbidden zone’ is the time period in the vicinity at which body temperature is highest, and it corresponds to peak muscle and exercise capacity.6 It is considered that this time zone occurs around 17.00 hours, and that exercise around this time is effective for improving the sleep quality of the elderly. It is also considered that exercise in the evening increases the activity of the arousal system in the ‘forbidden zone’. It is considered that arousal maintenance in the afternoon may be recovered by the short nap, and that the quality of daytime arousal in the elderly is improved by exercise in the evening, as demonstrated in the present study. As a result, the frequency of nodding before going to sleep decreased, and the quality of nocturnal sleep improved. After the ‘intervention’, mental health had also improved with improving sleep quality, as well as volition and physical health. The study’s results suggest that this ‘intervention’ technique is effective in improving the quality of life and the activity of daily living of elderly people.