Experts say most people do not make up for hours of sleep lost during the week by sleeping more on weekends. They say you cannot recover lost sleep time.
It is also true that some people need less sleep than others. The general belief is that fewer than six hours of sleep is not enough. Fewer than six hours of sleep over a few days can lead to a loss of attention, learning difficulties and memory loss.
Chronic lack of sleep can lead to heart disease and diabetes. Sleeping five or fewer hours of sleep can lead to hardening of the arteries. More sleep will not restore the damage.
Just one sleepless night can impair you. Driving performance goes down. Reaction times are slower.
There is a reason to believe that sleep can be interrupted without harm to the sleeper. Getting up in the middle of the night and going back to sleep an hour later will not hurt the sleeper. The total number of hours of sleep should be more than six hours.
There is good news. A 20-minute nap can equal an extra hour of night sleep. A good night’s sleep lowers blood pressure. These are healthy things.
Source: The New York Times July 24, 2015