Napping

Research summary

• Multiple independent dose-response meta-analyses of habitual daytime napping and health outcomes converge on a nuanced, U- or J-shaped pattern rather than a simple linear relationship: several analyses find longer or more frequent napping (often defined as more than 60 minutes, or napping most days) is associated with higher cardiovascular disease and all-cause mortality risk, while shorter, less frequent napping shows a more neutral or even modestly favorable association.
• A dedicated dose-response meta-analysis similarly links longer daytime napping to elevated stroke risk.
• One interpretation raised in this literature is that longer napping may partly reflect underlying poor nighttime sleep or undiagnosed illness (reverse causation) rather than napping itself causing harm — a genuine unresolved question in the field.
• Given this real complexity, the evidence does not support a simple "napping is good" or "napping is bad" conclusion; duration and context both appear to matter.