Research

Mixed

Long sleep duration (>8 hours) is associated with older age (especially in men), low physical activity, and poorer physical health scores, suggesting it may be an epiphenomenon of undiagnosed chronic comorbidity or fatigue rather than a protective behavior.

If you regularly sleep more than 8 hours, consider it a potential signal of underlying health issues, especially if you are older or less active. This study links long sleep with lower physical activity and poorer physical health. Instead of forcing yourself to sleep less, evaluate your physical health, check for undiagnosed conditions, and assess your activity levels. Long sleep may be your body's response to fatigue or illness.

GoodQualifiesMEDIUM confidence
For long sleep duration, there were fewer significant associations: age among men... low physical activity... and Short Form-36 physical score... Long sleep may represent an epiphenomenon of comorbidity.
Saverio Stranges et al. · American Journal of Epidemiology · 2008

Why this rating

Consistent findings across two populations, though statistical power is lower due to fewer long sleepers.

Source

Correlates of Short and Long Sleep Duration: A Cross-Cultural Comparison Between the United Kingdom and the United States: The Whitehall II Study and the Western New York Health Study

Saverio Stranges et al. · American Journal of Epidemiology · 2008

DOI 10.1093/aje/kwn337

cross_sectional · n=9499Cited 345×
Read the paper
DOI resolved against Crossref · corpus check 2026-06-10

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