Personalized sleep threshold studied

A study published in Sleep Medicine in October 2026 suggests that a personalized sleep threshold may better predict the health risks of short sleep duration than the universal guideline of six hours.

Study design and data collection

An international team from the National University of Singapore tracked 462 adults over nearly a year using sensors, including a connected ring worn on the finger, and daily phone-based questionnaires. These devices recorded sleep duration night by night more accurately than recall upon waking.

Study expanded to larger population

A second analysis expanded the study to 376,758 users of similar devices across seven countries. This larger sample allowed researchers to validate their findings on a broader scale.

Personalized sleep threshold explained

The study found that the risk of short sleep was determined by the deviation from an individual's usual sleep duration, rather than a fixed number of hours. The calculated personalized threshold averaged around 6.1 hours, very close to the traditional six-hour guideline, but identified different nights and different individuals as being at risk.

Health outcomes and effectiveness

According to one report, approximately 35% of nights were considered too short based on the six-hour rule, while 37% were identified as too short using the personalized threshold. The personalized approach correlated more closely with the actual health status of participants.