Study Challenges Sleep Duration Rule

A new study has shown that identifying short sleep is not only based on the number of hours slept but also depends on an individual's usual sleep pattern. Researchers from the National University of Singapore used smart rings and daily notes on 462 university employees for up to a year. They found that the frequency of short nights is associated with decreased alertness, increased stress, and poor mood, as well as higher blood pressure and arterial stiffening. Additionally, the use of the individual measure revealed clearer relationships, with a caution that the study's results are correlational and not causal. Further research is needed to verify the stability of personal thresholds, despite the limited data from participants.