You wake up from a night's sleep, or even from a nap. How alert do you feel? Perhaps you're groggy or in a daze for a while. That's the condition known as sleep inertia, and it's no time to make important decisions or do anything that requires concentration, like driving a vehicle or even using a hot stove or a sharp knife.
This poses problems for some people who are required to wake up and be alert. This includes physicians, truck drivers, pilots, military personnel and many other occupations.
A study done at the University of Boulder in Colorado and published in the Journal of the American Medical Association suggests that people perform worst within the first three minutes of awakening and previous study showed that sleep inertia might continue for up to two hours.
The effects of sleep inertia vary from person to person. Some people wake up alert and ready to go. Others may walk around in a daze for an hour or more. According to the Roads and Traffic Authority, sleep inertia can last from 1 minute to 4 hours, but typically lasts 15-30 minutes. It's dependent on how long you've been asleep and is worse if the person is sleep deprived or awakened from a really deep sleep.
Some things that may help a person overcome sleep inertia are strong coffee, a shower and breakfast. However, for someone like a physician, who finds it necessary to make fast and accurate decisions soon after wakening, there is often no time for coffee and a shower.
According to NASA, after doing research on how the length of sleep affected astronauts, discovered that test subjects on a nocturnal schedule felt more "sleep inertia" when waking up from a nap than after a full night's sleep.
Resources:
Journal of the American Medical Association
U.S. Roads and Traffic Authority
NASA
Work Safe Alberta
