A simple way to improve sleep for the elderly has been identified

Scientists from Japan found that taking a hot bath before bed improves sleep quality in elderly people. Participants who took a bath before going to bed slept deeper than their peers who did not adhere to this habit. The effect was especially pronounced during winter months. The work is published in the Sleep Health: Journal of the National Sleep Foundation.

The study involved 2252 residents of the Japanese city of Nara aged around 69 years, of which 64% were women. For a week, volunteers wore an actograph on their wrist - a device that records movement and allows for evaluating the duration and quality of sleep. At the same time, participants recorded their evening habits in a diary: whether they took a hot bath, shower, or did not bathe at all before sleep, as well as indicated the duration of bathing.

Hot baths are part of traditional culture in Japan. Usually, the water temperature reaches 40–41 °C, and the bath itself lasts from 10 to 30 minutes.

It turned out that those who took a hot bath before bed less frequently complained about poor sleep quality and, according to actography data, slept more effectively. Meanwhile, a shower did not provide a similar effect.

Scientists noted that the positive influence was enhanced with moderate water temperature and immersion time up to 18 minutes. With hotter water (above 41.7 °C) or too long bathing, the sleep improvement, on the contrary, decreased.

The study also showed that the optimal interval between bathing and sleep is from one to two hours. During this period, body temperature gradually decreases, which contributes to natural falling asleep.

The authors of the work explain the effect by the fact that immersion in hot water relaxes muscles, improves blood circulation, and helps reduce the activity of the sympathetic nervous system responsible for stress. In addition, a warm bath helps stabilize circadian rhythms and facilitates the transition to sleep.

"Our results show that taking a hot bath 60–120 minutes before sleep can improve sleep efficiency and reduce the number of awakenings, especially during the winter period," the scientists concluded.