This doesn’t mean you should compromise on your Shabbos shluf, but take note:
British researchers claim that sleeping longer than the recommended seven to eight hours nightly can lead to premature death.
Analysis of 74 studies involving over three million people indicated that sleeping over eight hours a night is associated with a moderate death increase. Sleeping nine hours raised the odds of death by 14%, and for 10 and 11 hours the figures increased to 30% and 47%.
Sleeping less than seven hours nightly had no significant effect, but poor sleep quality was associated with a 44% increase of heart disease.