How Much Zzz Do You Need?

#174

Regarding the number of hours of sleep one needs, various factors come into play - your age, your gender, your body type, your genetics, and the amount of cognitive load you're taking on daily.

The actual number of hours needed also depends on how well you want your brain to function, since your performance suffers significantly even with one night of staying up. In an experiment conducted with participants around sleep deprivation, the following results were seen: 

• The group that received 8 hours of sleep saw no change to their cognitive performance throughout the 2-week study
• After 10 days, the participants who had slept 6 hours each night were as cognitively impaired as those suffering from 1 night of total sleep deprivation
• The group that got 4 hours of sleep took 3 days before they reached that same level of impairment. After 10 days, they were as cognitively impaired as if they had gone 2 days with no sleep
• The group that slept 7 hours a night were dozing off at a rate 3 times more than the group sleeping 8 hours a night just 5 days into the experiment!

This is interesting, because a) you don’t know you are sleep deprived when you are sleep deprived and b) you cannot effectively train yourself to need less sleep. All you may get used to is feeling tired all the time. Bottom line, you won't be able to get away with suppressing your tiredness to perform as well on cognitive tests as you would if you had received the full 8 hours.

It's ironic when someone tells you the reason they can only get five hours of sleep is that they simply have too much to do because the entire reason they're probably slower at doing those things is due to lack of adequate sleep!

Fun fact about 'placebo sleep': If you tell people they slept better than they did, they are likely to perform better on math and word association tests.