Brain Sleep Co., Ltd. (Headquarters: Chiyoda-ku, Tokyo; Representative Director: Atsushi Hirota; hereinafter "Brain Sleep") announced the results of an analysis of "the impact of social jet lag and regularity of sleep/wake rhythms on sleep evaluation," conducted jointly with the Stanford Circadian Neurobiology Laboratory (SCNL), at the 32nd Annual Meeting of the Japanese Society for Chronobiology (hereinafter "the Society") held at the Kyoto Institute, History, and Culture Hall (Kyoto, Kyoto Prefecture) on October 4 (Sat) and 5 (Sun), 2025. Summary Large-scale data analysis using "Brain Sleep Coin" yielded the following results, confirming the importance of "regular sleep":1) The greater the shift in sleep rhythm between holidays and weekdays, the worse morning awakening and daytime physical condition tend to be.2) Daily sleep rhythm is also important, with irregular sleep rhythms tending to lead to a longer time to fall asleep. Background Recent research and survey data confirm that sleep rhythms between weekdays and weekends tend to be significantly disrupted, and this may directly lead to sleep quality and health risks. In particular, a large shift in sleep rhythm between weekdays and weekends can disrupt the body's internal clock, making it easy to fall into social jet lag (social jet lag), also known as "weekend jet lag."Furthermore, it has been pointed out that an "irregular lifestyle," where one goes to bed and wakes up at different times depending on the day, regardless of weekdays or holidays, not only disrupts the body's internal clock and hinders deep sleep, but also increases the risk of physical and mental health problems.The large-scale data analysis using "Brain Sleep Coin" aimed to clarify the specific effects of sleep rhythm shifts that cause social jet lag on the body, and to acquire and analyze scientific data to achieve better sleep quality in the future. Overview ＜Presentation Summary＞Date: October 4 (Sat) - 5 (Sun), 2025Venue: Kyoto Institute, History, and Culture HallTitle: The impact of social jet lag and regularity of sleep/wake rhythms on sleep evaluation: Large-scale data analysis using a waist-worn activity meter ＜Survey Summary＞Method: Survey using "Brain Sleep Coin"Target area: NationwideTarget conditions: All users who measured during the periodSample size: 7,419 peopleSurvey period: January - December 2024Analysis method: The sleep mid-point*1 of all data was calculated, and then divided into two groups: ① a group with a large difference and a group with a small difference in sleep mid-point between weekdays and holidays, and ② a group with a large difference and a group with a small difference in daily sleep mid-point, for comparative analysis. The results focused on three indicators that showed statistically significant differences: "Awakening mood score"*2, "Daytime condition score"*3, and "Time to fall asleep"*4. ※1 The midpoint of the sleep onset and wake-up times (e.g., if you sleep from 11 PM to 7 AM, the sleep midpoint is 3 AM) ※2 A 5-point rating question answered on the "Brain Sleep Coin" app about mood after waking up (higher score indicates better waking mood) ※3 A 5-point rating question answered on the "Brain Sleep Coin" app about condition on the measurement day (higher score indicates better daytime condition) ※4 The time it took to fall asleep from the start of measurement, as measured by the "Brain Sleep Coin" device Result ①: Impact of sleep rhythm shift between weekdays and weekends (social jet lag) It was confirmed that the greater the social jet lag, the worse the mood upon waking and the daytime condition. It was revealed that the group with a large social jet lag (top 30%) had statistically significantly lower awakening mood scores and daytime condition scores compared to the group with a small social jet lag (bottom 30%).The effects of social jet lag have been reported numerous times, including difficulty waking up in the morning and increased daytime fatigue, similar to this study. It is estimated that approximately 70% of the population experiences a 1-hour shift in sleep rhythm between weekdays and weekends due to social jet lag, and approximately 30% experiences a shift of 2 hours or more*5. The results of this study indicate the need to minimize the shift in sleep rhythm between weekdays and weekends. ※5 Roenneberg T, et al. (2012). https://doi.org/10.1016/j.cub.2012.03.038 Result ②: Impact of daily sleep/wake rhythm shifts (sleep regularity) It was confirmed that people with irregular sleep rhythms had worse morning conditions and took longer to fall asleep. It was found that the group with a large daily sleep rhythm shift (top 30%) had statistically significantly lower awakening mood scores and daytime condition scores, and statistically significantly longer time to fall asleep, compared to the group with a small daily sleep rhythm shift (bottom 30%).It has been reported that irregular sleep rhythms disrupt the body's internal clock and have a negative impact on health. Furthermore, irregular sleep rhythms can lead to difficulty falling asleep, forming a vicious cycle of "sleep deprivation → decreased daytime performance → irregular sleep rhythms." One study reported that sleep rhythm regularity plays a greater role in healthy longevity than simply getting enough sleep*6, suggesting that "regularity" in addition to "quality" and "quantity" of sleep is key to healthy longevity. ※6 Windred DP, et al. (2023). https://doi.org/10.1093/sleep/zsad253 The 32nd Annual Meeting of the Japanese Society for Chronobiology - Overview Dates: October 4 (Sat) - October 5 (Sun), 2025Venue: Kyoto Institute, History, and Culture HallTheme: "Chronobiology for Life, Society, and the Earth"President: Kazuhiro Yagita, Kyoto Prefectural University of MedicineOfficial Website: https://chronobiology.jp/ What is "Brain Sleep Coin," a sleep measurement tool? This sleep measurement tool, which assigns value to sleep, is equipped with a unique measurement algorithm developed based on data accumulated through sleep research. It enables more personalized analysis tailored to human movement, and supports improved sleep quality by proposing a positive cycle where sleep scores are converted into coins for better sleep habits. 1. Measure: Analyze sleep states with unprecedented accuracy Incorporates a proprietary algorithm developed based on sleep research, applying technology used in sleep research. It reveals your sleep stage (depth of sleep), sleeping posture, snoring/environmental sounds, and bedding temperature (temperature inside the futon), which were not visible with conventional sleep measurement applications. 2. Improve: Personalized advice Identifies problems based on your sleep state and displays advice to improve sleep.Provides improvement suggestions based on daily sleep conditions to support better sleep. 3. Accumulate: Earn coins every time you sleep Your sleep condition and good sleep habits are converted into sleep coins. Accumulated sleep coins can be exchanged for discount coupons for Brain Sleep products, music purchases within the app, and more. ＜Product Details＞ Product Name: Brain Sleep CoinPrice: App is free, device is 8,800 yen (tax included)URL: https://brain-sleep.com/products/coin
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