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Tracking Long-Term Sleep and Activity Differences across Chronotypes: A Case Study in Finland Using Oura Rings

  • Chandreyee Roy *,   
  • Kunal Bhattacharya,   
  • Kimmo Kaski

Received: 13 Mar 2026 | Revised: 18 May 2026 | Accepted: 22 Jun 2026 | Published: 09 Jul 2026

Abstract

Non-invasive mobile wearables like fitness trackers, smartwatches, and smart rings allow for an easy and relatively less expensive approach to studying patterns of everyday human sleep and activity patterns compared to traditional longitudinal methods. We used smart rings manufactured by Oura to obtain granular data from 19 healthy participants over the time span of one year (October 2023–September 2024), to investigate longitudinal sleep and activity patterns of three chronotype groups among them: morning type (MT), neither type (NT), and evening type (ET). We find that while ET individuals do not seem to lead as healthy patterns as MT or NT individuals in terms of overall sleep and activity, they seem to have significantly improved their habits over the duration of the study. The activity in all chronotype groups varies throughout the year with the ET individuals showing an increasing trend. Furthermore, we show that the Daylight Saving Time changes in autumn affect the sleep quality of the MT individuals. Finally, using a mixed-effects regression model, we show that the perceived stress of an individual is significantly associated with their time spent in bed during nighttime sleep, monthly survey response time, chronotype and age, while accounting for individual variability.

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Roy, C.; Bhattacharya, K.; Kaski, K. Tracking Long-Term Sleep and Activity Differences across Chronotypes: A Case Study in Finland Using Oura Rings. Journal of Social Physics 2026, 1 (1), 7. https://doi.org/10.53941/jsp.2026.100007.
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