How Much Sleep Is Enough?
Researchers are finding that a person’s sleep need has two components:
Basal sleep need – the 8 or 9 hours of sleep healthy people need on a regular basis for optimal performance, and
Sleep debt – the accumulated sleep that is lost to poor sleep habits, sickness, awakenings due to environmental factors or other causes.
These needs work together. You might meet your basal sleep need on any single night or a few nights in a row, but still have an unresolved sleep debt that may make you feel sleepy or dull at times,
On top of that, circadian dips occur during the day (mid-afternoon) and night when we are biologically programmed to be more sleepy and less alert.
During these circadian dips we risk falling asleep because of sleep debt – while operating machinery at work, at an afternoon meeting, while driving a car….
The good news: some research suggests that we can “pay off” the accumulated sleep debt.
Source: National Sleep Foundation
