Brain Sleep Co., Ltd. (Head office: Chiyoda-ku, Tokyo; Representative Director: Atsushi Hirota; hereinafter "Brain Sleep") has been conducting a "Sleep Deviation Score®" survey since 2020, targeting 10,000 people (allocated by gender, age, and prefecture) across all 47 prefectures nationwide. The survey entered its seventh year in 2026. The Sleep Deviation Score is a method that comprehensively scores sleep status, including sleep habits and sleep debt, as well as productivity, stress levels, and the risk of sleep apnea syndrome (SAS). Moving forward, we will utilize the results of this survey to undertake various activities aimed at further improving sleep in Japan.Sleep Deviation Score® Survey Results Page https://brain-sleep.com/pages/research2026 ■Survey Results Brain Sleep has been continuously assessing the sleep conditions of Japanese people by establishing a "Sleep Deviation Score®" based on various sleep-related metrics. Furthermore, based on evidence-backed insights and the latest survey data, we are promoting the development and deployment of sleep-related services and products. This time, we measured the 2026 "Sleep Deviation Score®" and identified characteristics of Japanese sleep in the following five new categories:1. Changes in Japanese sleep duration2. Sleep characteristics of people in their 20s3. Fatigue and its solutions4. Relationship between performance and sleep5. Gender commonalities and perceived differences in daytime changes brought about by good sleep1. Changes in Japanese sleep duration: Average sleep duration is 6 hours and 41 minutes. Sleep duration falls significantly below healthy levels, worsening to the second worst in survey history.Since the COVID-19 pandemic, the average sleep duration of Japanese people has shown a gradual increase. However, a 2026 survey targeting 10,000 employed individuals revealed that the average sleep duration was 6 hours and 41 minutes, making it the second worst result in the survey's history, after 2020. This represents a significant decrease from the previous year's 6 hours and 50 minutes, indicating that the improving trend has reversed again. This level is significantly below the recommended sleep duration for maintaining health, and it remains overwhelmingly shorter compared to the average sleep duration of 8 hours and 28 minutes in OECD member countries. The structural issue of Japan's sleep duration being among the lowest globally remains unaddressed. *One-way ANOVA was performed on all data, and significance was confirmed (p<0.01). For the comparison of sleep duration with the previous year, t-tests with Bonferroni correction were performed, and a significant difference was confirmed for 2020-2024 and 2025-2026 (both p<0.01). For the comparison of 2025-2026, Welch's t-test was performed for bedtime and overtime hours (average), and a significant difference was confirmed (both p<0.01). This survey revealed a delay in bedtime and an increasing trend in overtime work as factors contributing to the decrease in sleep duration. In recent years, as companies increasingly return to in-office work, it is possible that longer commuting times and working hours are affecting people's daily rhythms. This suggests that the sleep duration, which had temporarily improved due to the spread of remote work, may be deteriorating again with changes in social structures. 2. Sleep Characteristics of People in Their 20s: Those in their 20s invest in sleep, are the "only group with over 7 hours of sleep," and have high sleep awareness, making them "sleep high achievers." However, their challenge is a "catch-up sleep rhythm" where they recover on weekends.Among all age groups, people in their 20s were the only ones with an average sleep duration exceeding 7 hours, displaying characteristics of "sleep high achievers." This is attributed to a high awareness of sleep as a "resource to be managed," with many prioritizing sleep even during busy periods, actively seeking information about sleep, adjusting pre-sleep behaviors, and being proactive in investing time and money in sleep. However, it was also revealed that their average wake-up time is relatively late, and there is a significant difference between their weekday and weekend sleep durations, with weekend sleep being more than two hours longer compared to weekdays. This indicates that while they secure sufficient sleep quantity, they also exhibit an unstable sleep rhythm that relies on "catch-up sleep" on weekends. *Welch's one-way ANOVA was performed on sleep duration, bedtime, and wake-up time, and a significant difference by age group was confirmed (p<0.05). People in their 20s had the longest sleep duration and the latest wake-up time (Welch's t-test for 20s vs. other age groups, p<0.05). *A χ² test was performed on sleep awareness and behavior (20s/30s/40s/50s/60s × applicable/not applicable), and significance was confirmed for all indicators (p<0.05). Furthermore, "actively collecting information about sleep" and "willing to spend time and money on sleep in the future" were significantly higher for people in their 20s than for other age groups (χ² test for 20s vs. 30-60s, both p<0.01). The 20s age group is the only one with an average sleep duration exceeding 7 hours, and their high awareness of sleep as a crucial resource for self-management is also evident. In this survey, regarding sleep awareness and behavior, the 20s age group showed the highest levels across all generations for all items, including "prioritizing securing sleep even when busy," "actively collecting information about sleep," "spending money and making efforts for sleep," "adjusting pre-sleep behaviors for sleep," and "willing to invest time and money in sleep in the future," demonstrating the potential of "sleep high achievers."Furthermore, regarding restorative feeling over the past month, the 20s age group had the highest response rate for "feeling rested through sleep" among all age groups. In terms of sleep quality and sleep duration, the proportion of those who answered "very good/good" was the second highest after the 60s age group (sleep quality 53.8%, sleep duration 56.3%). This suggests that a relatively large proportion of individuals in this age group subjectively feel "they are getting enough sleep" and "they are well-rested." *Regarding the extension of sleep duration on holidays, the 20s group was significantly lower in "no change" and significantly higher in "2 hours or more" compared to other age groups (χ² test for 20s vs. 30-60s, both p<0.01). On the other hand, it also became clear that their wake-up time is the latest among all age groups, and there is a significant difference between weekday and holiday sleep durations, with a difference of more than two hours. As a result, a "catch-up sleep rhythm" was observed, where they sleep longer on weekends, indicating a tendency for their daily rhythm to fluctuate throughout the week. While being "sleep high achievers" who balance sufficient sleep duration with a proactive attitude towards sleep, challenges remain, such as their late wake-up times and the largest difference in sleep duration between weekdays and holidays among all age groups, suggesting a reliance on weekend catch-up sleep and a tendency towards an unstable daily rhythm. 3. Fatigue and its solutions: 80% of Japanese people experience fatigue, with "sleep" being the number one solution.When asked about their condition over the past month, approximately 80% of respondents answered "always tired," "often tired," or "sometimes tired," indicating that most people experience fatigue on a daily basis. *Individuals who felt fatigued: those who responded "always tired," "often tired," or "sometimes tired" to the frequency of feeling fatigued in the past month.*A χ² test was performed for sleep quality × presence of fatigue, and a significant difference was confirmed (p<0.01). The proportion of individuals with fatigue monotonically increased as sleep quality worsened, and a significant trend was confirmed (p<0.01). This survey analyzed the proportion of people experiencing fatigue based on sleep quality. The results confirmed that those who answered "very good" or "good" experienced less fatigue, while the proportion of those feeling fatigued significantly increased as sleep quality deteriorated to "bad" or "very bad." This clearly re-demonstrates a strong correlation between higher sleep quality and less fatigue. These findings suggest that not just securing rest time, but "high-quality sleep" is crucial for reducing fatigue.Furthermore, the most frequently chosen coping mechanism for fatigue was "getting sleep (going to bed early/lying down on the spot)," suggesting that many people choose sleep as their primary means of recovering from fatigue. This behavioral aspect further substantiates the central role sleep plays in fatigue reduction. 4. Relationship between performance and sleep: The overall factor of "sleep (quantity, quality, regularity)" has the most significant impact.Looking at individual factors that influence daytime performance, "mental stability (21.3%)" and "sleep quality (16.3%)" ranked high. However, when combining sleep-related factors, "sleep quantity, quality, and regularity" accounted for 30.6%, making it the largest proportion among single lifestyle domains. This result suggests that many people perceive sleep not as a single action, but as a comprehensive foundation for life that includes quantity, quality, and rhythm, recognizing it as a crucial factor that comprehensively impacts concentration, physical condition, and mood stability. *Regarding the extension of sleep duration on holidays, the 20s group was significantly lower in "no change" and significantly higher in "2 hours or more" compared to other age groups (χ² test for 20s vs. 30-60s, both p<0.01). When comparing sleep regularity and performance indicators (body, mind, brain), the regular group showed higher scores in all three areas compared to the irregular group. Furthermore, when comparing by sleep duration, the group that "regularly" secured "7-8 hours" of sleep showed the highest scores in all items. In contrast, groups with irregular sleep or those with extremely short/long regular sleep tended to have lower performance. *Welch's t-test was performed for sleep regularity (regular/irregular) and performance (body, mind, brain), and a significant difference was confirmed for all (all p<0.001). For the group with regular sleep (n=5,634), performance (body, mind, brain) was compared across 5 sleep duration categories, and a significant difference between groups was confirmed by Welch's one-way ANOVA (all p<0.001). The average was highest in the 7-8 hour group for all three indicators, and the 7-8 hour group was significantly higher than both the less than 6 hours and 9 hours or more groups (after Holm correction, p<0.05). These results suggest that merely sleeping for a long time is not sufficient; both "appropriate sleep duration" and "regular sleep rhythm" are essential for maximizing daytime performance. Maintaining sleep quantity, quality, and regularity can be considered a crucial lifestyle habit directly linked not only to physical health but also to cognitive function and mental health. 5. Gender commonalities and perceived differences in daytime changes brought about by good sleep: Commonalities exist between genders, with women tending to experience stronger perceptions.We analyzed how good sleep affects daytime physical and mental states and behaviors, broken down by gender.The results showed that the most common change cited by both men and women was "waking up feeling refreshed in the morning," followed by "feeling physically well," "reduced frequency of feeling sleepy," "increased work efficiency," and "feeling mentally well." The composition of these top-ranking items was largely similar between genders. This suggests that the main effects of good sleep are common regardless of gender, broadly contributing to improved daytime alertness, physical condition, cognitive performance, and psychological state.Furthermore, comparing the gender differences for each item, the differences were all around a few percent, with no significant discrepancies, confirming that the core effects of good sleep are broadly consistent between men and women.On the other hand, the proportion of women slightly exceeded that of men in almost all items, suggesting that women tend to experience the changes brought by sleep somewhat more strongly. This difference was relatively prominent in items such as improved morning wakefulness, improved physical and mental condition, and improved skin condition, suggesting that women may be more sensitive to physical and mental changes due to sleep, or may possess characteristics that make them more receptive to the benefits of sleep improvement.Overall, while good sleep provides a fundamental performance-enhancing effect common to both genders, it was revealed that there is a gender difference in the intensity of this perception. Sleep is a crucial factor supporting the quality of daytime life regardless of gender, and at the same time, its effects tend to be perceived more strongly, particularly by women. ■Comment by Dr. Seiji Nishino, Brain Sleep Chief Research Advisor and author of "The Stanford Way to a Restful Sleep" The results of this year's "Sleep Deviation Score®" survey once again demonstrate the "interrelationship between sleep quality and social structure" that we have pointed out for many years. The re-shortening of average sleep duration due to factors such as the return to office work after the COVID-19 pandemic, and the associated delay in bedtime and increase in overtime hours, signifies that social factors significantly influence sleep hygiene improvement, which cannot be solved by individual effort alone. On the other hand, the high sleep literacy and willingness to invest in sleep seen in people in their 20s offer hope and indicate the potential for overall societal sleep improvement through intergenerational learning. The important thing is not simply to aim for "longer sleep," but to simultaneously optimize appropriate sleep duration, regularity, and quality. Companies and governments should seriously consider redesigning commuting and working hours and implementing workplace sleep support measures, and we researchers need to proceed with verifying evidence-based concrete interventions. In addition, we aim to further concretize our recommendations by conducting detailed analyses by region, industry, and work style. Sleep is crucial social capital directly linked to the productivity and happiness of individuals, companies, and nations. ■"Sleep Deviation Score®" Survey Results Page https://brain-sleep.com/pages/research2026Brain Sleep can provide various information regarding this survey.*When using the contents of this survey, please be sure to cite the source as ""Sleep Deviation Score®" Survey 2026 (n=10,000) by Brain Sleep." ■About this survey When evaluating sleep, the focus is often on simple quantitative data such as sleep duration. However, Brain Sleep believes that sleep should be viewed from a more multifaceted and comprehensive perspective. Therefore, we designed a set of questions to quantify sleep status from a broad range of perspectives, including subjective aspects such as self-reported symptoms and daily sleep habits. By converting this into a numerical value using the "deviation score," a metric familiar to Japanese people, we established the "Sleep Deviation Score®" system, which allows for a relative understanding of an individual's sleep status within society as a whole.This survey is continuously conducted under the supervision of Dr. Seiji Nishino, a leading sleep researcher and our Chief Research Advisor, with an emphasis on scientific validity. Brain Sleep believes that accurately understanding sleep conditions is the foundation for improving overall societal health and performance. We have therefore accumulated data through long-term surveys, not just short-term initiatives.Moving forward, we will continue to visualize the latest sleep conditions and contribute to understanding and improving sleep issues in Japan by returning evidence-based insights to society. [Survey Overview]Survey Method: Web survey Region: Nationwide Target Audience: Men and Women Sample Size: n=10,000ss Survey Period: January 2026*For comparisons of Sleep Deviation Scores and other scores between groups, one-way ANOVA or t-tests were performed, and a significance level of 5% or less was determined as a statistically significant difference and reported.
Log in
