Acute sleep rebound following sleep restriction is associated with reduced mortality risk.

Public health guidelines recommend 7-9 hours of regular sleep and suggest weekend catch-up sleep after weekday sleep deficits. However, real-world sleep patterns are more complex than laboratory-studied models or simple weekday-weekend cycles. Epidemiological evidence on the necessity of acute rebound after restriction remains limited. In this prospective cohort study of 85,618 UK Biobank participants (mean [standard deviation] age 61.8 [7.8] years), we analyze accelerometer-derived sleep data and identify five day-to-day sleep restriction-rebound patterns: regular sleep, sleep restriction (SR) without rebound, SR with rebound, severe SR without rebound, and severe SR with rebound. Associations with all-cause mortality are examined over a median 8.0-year follow-up. Compared to regular sleep, severe SR without rebound is associated with higher mortality risks in the overall sample and across baseline sleep duration groups. SR without rebound is linked to higher mortality overall and in short sleepers. Conversely, neither SR with rebound nor severe SR with rebound is significantly associated with mortality. Results are replicated in an independent cohort from the National Health and Nutrition Examination Survey (N = 4,586). Our findings suggest that short-term SR might be detrimental, particularly for short sleepers, and highlight acute sleep rebound as a potential strategy to mitigate mortality risk.