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To sleep soundly in a limited amount of time and efficiently prepare your body, it is crucial to focus not only on bedding such as futons and pillows but also on your sleep environment. By being mindful of room temperature, humidity, bed temperature, light, and sound during sleep, you can achieve higher quality sleep than ever before.
This article introduces key points for creating a comfortable sleep environment and excellent items that will enhance your daytime performance.
Masahiro Nakajima
Ph.D. in Science / Director and CFO of Brain Sleep Inc. / Senior Sleep Health Instructor
Born in Yamaguchi Prefecture in 1983. Graduated from the Department of Physics, Faculty of Science, the University of Tokyo in 2007, and completed his Ph.D. in Physics from the Graduate School of Science, the University of Tokyo in 2012. Joined Brain Sleep Inc. as a director upon its establishment in May 2019. As CFO, he oversees financial aspects and sleep consulting-related businesses for partner companies. He also manages sleep research based on the results of sleep-related epidemiological surveys published as "Sleep Deviation Score" and supports corporate health management. Obtained Senior Sleep Health Instructor certification in November 2021.
Is a good sleep environment important for achieving quality sleep?
There are mornings when you wake up refreshed and feel well-rested, and other days when, despite sleeping for the same amount of time, you wake up groggy and don't feel rested. This might be related to the quality of your sleep.
The "Sleep Guidelines for Health Promotion 2014" issued by the Ministry of Health, Labour and Welfare's Health Bureau states that "creating an environment is also important for good sleep."
It notes that room temperature, humidity, and bed temperature affect sleep onset and depth, and that the bedroom lighting before sleep and the sound environment during sleep can reduce sleep quality, thus emphasizing the importance of the sleep environment.
In other words, to achieve quality sleep, a comfortable sleep environment that facilitates quick sleep onset and minimizes awakenings during the night is essential.
Four key points for creating a sleep environment
To achieve quality sleep, it's important to prepare your sleep environment. Here are four points related to light, sound, bedding, and room temperature that promote relaxation and smooth sleep onset.
1: Room brightness (light)
There is a close relationship between sleep and room brightness. Melatonin, a hormone that promotes sleep and is secreted at night, has its secretion suppressed when exposed to high-intensity light, awakening the brain and hindering smooth sleep onset. Therefore, avoid strong light for an hour before bedtime.
Color temperature is also important. Before going to bed, warm-toned lights closer to orange with a lower color temperature are recommended over cool-toned lights (white to blue) with a higher color temperature. Relax with a soft, reddish light that isn't too bright.
If you prefer not to sleep in complete darkness, it's recommended to adjust the light by placing indirect lighting away from your face.
2: Sound
During sleep, a sound environment of generally 40 dBA (decibels A) or less is desirable. Sounds above 40 dBA can affect sleep, and it is said that half of people will have their sleep disturbed by sounds above 50 dBA.
A sound level of 40 dBA or less is comparable to the quietness of a library or the rustling of leaves in the wind. A sound level of 50 dBA or more is comparable to the noise from household appliances such as a ventilation fan, TV, or the opening and closing of a door.
Listening to relaxing music before going to bed is considered beneficial, but falling asleep with the TV or radio on can promote wakefulness and degrade sleep quality. Therefore, when sleeping, block out noise from outside the house and turn off the TV and radio.
In a dark, silent environment with minimal sensory stimulation, alertness can increase, making it difficult to sleep due to heightened awareness of minor sounds, anxiety, or tension. If small sounds from electronic devices bother you and prevent you from sleeping, it's recommended to play healing music for sleep and set a timer for it to turn off.
3: Bedding
To sleep comfortably until morning, pay attention to your bedding.
Choose a mattress and pillow that suit your body type and sleep concerns, and consider the feel, lightness, and warmth of your duvet. Furthermore, by choosing bedding with excellent moisture absorption and release properties, you can avoid accumulating moisture and achieve quality sleep.
Also, instead of wearing casual T-shirts or sweatpants, choose pajamas that can enhance your sleep quality. Pajamas lack unnecessary embellishments and constrictions, making it easier to turn over in bed.
4: Room temperature
The ideal bedroom temperature is said to be around 25-27°C in summer and 15-18°C in winter, with humidity at 50-60% year-round. Also, a bed temperature of around 30°C and humidity of around 50% are considered comfortable.
At sleep onset, drowsiness is promoted by a drop in core body temperature, so pay attention to room temperature and humidity. If the temperature is too low or too high, core body temperature will not drop, leading to difficulty falling asleep and increased awakenings during sleep, which can degrade sleep quality.
Also, since outside temperatures differ between summer and winter, adjust your sleep environment using bedding, air conditioning, and humidifiers as appropriate for each season.
Summer sleep environment
The ideal indoor temperature for summer is around 25-27°C. There can be hot nights like tropical nights, or cool days with rain, so adjust your air conditioning to around 26-28°C to maintain a comfortable indoor environment.
To facilitate falling asleep, it is also important to cool down the bedroom before going to bed. At this time, if you pull back the duvet, the inside of the bed will also cool down, allowing you to sleep smoothly.
Winter sleep environment
The ideal indoor temperature for winter is around 15-18°C. As bedroom temperatures in winter would naturally be around 10°C, use heating to warm the room. In winter, physical activity tends to decrease, making it harder to meet the conditions for quality sleep, so it's essential to properly prepare your indoor environment.
Recommended products to support a comfortable sleep environment
To achieve comfortable sleep, various aspects of the sleep environment need to be adjusted. Here, we introduce Brain Sleep items that help regulate light, sound, room temperature, bed temperature, and humidity.
Visualize your sleep to improve your sleep environment!
To achieve quality sleep, creating the right sleep environment is crucial. To find out if factors like room temperature, humidity, light, sound, bedding, and pajamas are suitable for you, why not try measuring your sleep?
【Reference】
※ Ministry of Health, Labour and Welfare Health Bureau "Sleep Guidelines for Health Promotion 2014"
