In today’s busy world, many people think that they can sneak a few more precious hours into the day simply by foregoing a little bit of sleep, either going to bed late or getting up early. But even a seemingly small amount of sleep deprivation carries a hefty price tag when it comes to safety.

Researchers at the University of Pennsylvania School of Medicine conducted a study in 2003, which found that cognitive functioning declines considerably with fewer than eight hours of nightly sleep. Study participants slept for four to six hours per night for 14 straight nights. During daytime hours, they reported feeling only slightly sleepy.

But cognitive tests showed that the study participants’ cognitive performance was as low as if they had not slept at all for three nights in a row! The participants were completely unaware of how impaired their functioning was. Their cognitive shortcomings induced by sleep deprivation included:

• An inability to think quickly
• Being highly prone to make mistakes
• An inability to multi-task
• An inability to pay attention and react in a proper and timely fashion to a stimulus, such as when monitoring airplane traffic or driving a motorized vehicle³

The University of Pennsylvania study also found that the average person needs slightly more than eight hours of sleep every single night to prevent cognitive impairments from becoming cumulative.

Another study found that cognitive functioning declines by a whopping 38 percent following four nights of extreme sleep deprivation. Forty study participants slept for a mere 26 minutes each night for four consecutive nights. Cognitive tests administered following the sleep deprivation scored 38 percent lower than those administered prior to the sleep deprivation.

Getting plenty of shut-eye is critical for working memory. The working memory center in the brain retains information, then processes it for more involved mental functioning, such as decision-making and reasoning.

Night shift workers are more likely to suffer from insomnia than daytime workers. That’s because their sleeping hours are working against the body’s natural circadian rhythm, an internal clock that is set by the rising and setting sun. Night shift workers and their associated insomnia renders them more accident prone; in particular, motorized vehicle accidents are more prevalent amongst night shift workers than daytime workers.

A 2006 study published in the journal Sleep found that workers suffering from insomnia exhibit a markedly greater absenteeism rate. Workers with insomnia are absent 5.8 days every year, while workers who enjoy sufficient nightly rest are only absent 2.4 days per year. A full 50 percent of workers with insomnia are absent for at least one day during a two-year period, while only 34 percent of workers with adequate sleep are.

This may not sound like much, but it carries a real price. One insomniac employee’s absences can cost an employer an average of $3,025 annually. On the other hand, a well-rested employee’s absences cost an employer an average of only $1,250 annually.

Sleep isn’t a luxury, it’s a necessity. Adequate nightly rest helps you feel great, function at your best and prevent injuries.

Sources

1. National Institutes of Health. (2003). Sleep Deprivation Takes a Toll: Only 4-6 Hours Is Not Enough.
2. Wikipedia Web site: http://en.wikipedia.org/wiki/Sleep
3. SleepDeprivation.com: Symptoms and Causes of Insomnia.
4. Associated Professional Sleep Societies. (2006). Study in the Journal Sleep Shows that Insomnia Leads to Higher Rate of Absence at Work.