What are you like when you wake up in the morning? Do you wake up refreshed, ready to hop out of bed and start a productive day? Or do you wake up groggy, still tired, feeling disoriented and “not quite awake” until after your morning coffee, or for even longer?
If you fall into the latter category, you may be feeling the effects of sleep inertia. Sleep inertia is a temporary physiological state that is characterized by feelings of disorientation, reluctance or inability to get up, and a deficit of motor skills and decision-making ability. These symptoms usually last from 1 to 30 minutes, but can persist for as long as four hours. While we all experience some amount of sleep inertia immediately after waking up, it is much more pronounced among those of us who are chronically under-rested and who need alarm clocks to wake up in the mornings. Sleep inertia can also affect those who take regular naps, often leaving people feeling more tired after the nap than before it.
Sleep inertia may actually become dangerous, particularly when an individual doesn’t recognize the symptoms or realize that he or she is not functioning well. A study at the University of Colorado at Boulder found that people who suffer from sleep inertia have more impaired thinking and memory skills than people deprived of sleep for 24 hours. Sleep inertia can lead to being chronically late to school or work and may result in lower productivity once you get there. Even worse, coping with sleep inertia while going about your daily activities can raise the risk of accidents and injuries, including auto accidents (a growing number of which are related to “drowsy driving”).
The cause of sleep inertia is still unknown, but researchers can pinpoint when it happens. It occurs when a person is awakened suddenly from a period of slow-wave sleep, the deepest phase of the normal human sleep cycle. It has been theorized that sleep inertia may be caused by a buildup in the brain of adenosine, a chemical that is strongly linked to feelings of tiredness. This may explain why many people “self treat” their feelings of grogginess and disorientation after waking with coffee, because caffeine blocks adenosine receptors in the brain. Another “self treatment” that is common is resorting to the use of extremely loud alarm clocks, which shock the body and cause it to release adrenaline, thus speeding the wakening process.
Unfortunately, both of these “treatments” can have negative effects on your health, especially if you have to resort to them for years. Among the more effective methods of reducing the symptoms of sleep inertia and of preventing it are the following suggestions from sleep experts:
- Get up immediately after waking; if you need to hit the “snooze” button, do it for only 5 minutes and then force yourself to get up.
- Open your blinds or curtains before you go to bed; morning light fights sleep inertia.
- Maintain a regular schedule, both during the work week and on weekends; your circadian rhythms are sensitive, and disrupting them can lead to sleep inertia.
- Avoid caffeine in the evenings, but drink it on waking if you find it helps.
- Get sufficient exercise, but not late at night; morning exercise may actually help.
- Consider a “smart” alarm clock that tracks your sleep cycles and wakes you at the “right” time during the sleep cycle to avoid sleep inertia.
The best general advice may be to get to sleep at an appropriate hour and then to ignore any promptings from your own body to go back to sleep after you first wake up in the morning. Instead, get up and get active. The sooner you do that, the sooner the symptoms of sleep inertia will go away.