Six Hours of Sleep Can Be As Bad As Not Sleeping at All.
If you only get six hours of sleep every night, you might be as sleep-deprived as someone else got zero hours of sleep for two days.
This is what researchers at the University of Pennsylvania School of Medicine found in their study of sleep. They took 48 adults (ages 21-38) and limited their sleep to four, six, or eight hours each night for two weeks. One unfortunate group was forced to stay awake for three whole days.
For each group, the researchers tested participants’ cognitive ability and reaction time every two hours while they were awake.
Unsurprisingly, those who slept a full eight hours performed better, while those who slept only four hours a night got worse every day. The biggest surprise for the group was six hours of sleep. As Fast Company reports:
The group, which slept for six hours, appeared to be on their own until about day 10 of the study.
In the last few days of the experiment, subjects who were not allowed to sleep for a maximum of six hours a day had as poor cognitive abilities as people who were not allowed to sleep at all. Sleeping only six hours was as bad as not sleeping two days in a row. The group, which slept only four hours each night, performed similarly poorly, but peaked earlier.
The study used a small sample and some people seem to have little sleep. However, one of the findings of a 2004 study was that the participants in the six-hour group did not even think they were so drowsy, even though they had lower scores on tests. So perhaps consider whether you are really getting enough sleep .
Cumulative cost of extra wakefulness: Effect of dose on neurobehavioral function and sleep physiology as a result of chronic sleep restriction and complete sleep deprivation. | Sleep through Fast Company