Tech Doctor Establishes Activity, Sleep, and Heart Rate Variability Benchmarks from Wearable Data of 2,000 Japanese Workers

Tech Doctor (CEO: Kazunori Minato, Headquarters: Chuo-ku, Tokyo) has established age- and gender-specific benchmarks for activity, sleep, and heart rate variability by analyzing wearable data collected from approximately 2,000 employees of research-cooperating companies over a 15-month period. These research results were presented at the 99th Annual Meeting of the Japan Society for Occupational Health (held May 27-30, 2026).

In this study, using over 500,000 person-days of data obtained from Google Fitbit, benchmarks (median and 95% prediction intervals) were established for 16 metrics related to activity level, sleep, and heart rate variability among the Japanese working population. The study suggested associations not only with aging, gender differences, and temperature changes but also with medical history and metabolic syndrome, demonstrating the potential for personal monitoring and health guidance using wearable data.

Research Background Recently, the use of daily data from wearable devices has progressed, with many reports of links to health status and disease risk. For instance, meta-analysis has shown significant reduction in risk of all-cause mortality and chronic disease through increased steps. However, to utilize wearable data for health management and disease prediction, benchmarks are needed to determine if values are within a 'normal range.' In Japan, large-scale studies on these benchmarks have been limited.

Research Methods Participants: 1,996 employees (1,260 men, 736 women) aged 25 to 65 working in companies. Devices/Period: Google Fitbit data from Jan 2023 to Nov 2025 (Average duration: 435 days).

Research Results ・Heart Rate Variability (SDNN): Males had higher median values at young age (32ms vs. 27ms at age 25). Values decreased with age, with a steeper decline in males, and gender differences narrowed by age 60. ・Activity: Steps were consistently higher in males. Total Physical Activity (TPA) showed an increasing trend with age. ・Sleep: Sleep duration decreased with age in both genders. The proportion of deep sleep also declined. ・Associations: Lower heart rate variability and higher heart rates were confirmed in groups with medical history or metabolic syndrome.