Many studies indicate that the average American adult needs eight to nine hours of sleep a night. But the average shift worker (including night shifters and people who work rotating shifts) gets about six and a half hours of sleep per night, according to the National Sleep Foundation's 2000 Omnibus Sleep in America Poll.
Among shift workers and regular day time employees, almost half (45%) of those polled said they sleep less to get more work done. (Watching TV and Internet use were other reasons for not getting eight hours of sleep!)
Sleep Debt and the Physiological Effects
Add up the hours of sleep you're missing each night and that is your personal sleep debt, experts say. But the effects of being sleep deprived go beyond crankiness and the dark circles under your eyes.
One recent sleep study funded by the MacArthur Foundation concluded that as little as a weeklong sleep debt of three or four hours a night hurts people's ability to process carbohydrates, manage stress, and fight off infections, as reported in the Science Section of the New York Times (December 28, 1999).
In the study by Dr. Katrine Spiegal, Dr. Eve Van Cauter, and Rachel Leproult, subjects slept three 8-hour nights, and then their sleep was restricted to four hours each night for the next six nights.
At the end of the study, researchers found that symptoms of sleep deprivation mimicked some hallmarks of aging. For example, they found blood levels with higher amounts of cortisol, a measure of stress which is typical of the aging process and also associated with adverse health effects including memory impairment. (Certainly defeats midnight test cramming, doesn't it!) The Chicago-based team of researchers is furthering their studies on sleep deprivation among women and older adults.
In addition, it is well-documented that sleep deprivation can cause shift workers a higher rate of digestive problems such as constipation, diarrhea, excessive gas, abdominal pain, and heartburn, according to Circadian Technologies, Inc., a consulting agency and resource for 24-hour businesses.
Mental Lapses from Sleep Deprivation
Still, many people believe their bodies can adjust to shift work and less sleep without any performance tradeoff.
Dr. David Dinges, sleep researcher at the Institute of Pennsylvania Hospital and the University of Pennsylvania, studied people with chronic sleep loss and found they performed poorly on tasks, despite the fact that they felt they had adapted to the shorter amounts of sleep.
Sleep Deprivation Record Breakers
Until recently, most sleep research tested the limits of how long people can stay up and the short term effects of sleep deprivation.
Notorious cases of record-setters include disc jockey Peter Tripp who in 1959 stayed up for more than eight days as a promotional stunt. After a few days, he began to hallucinate, seeing kittens, mice, and cobwebs. He also became paranoid, insisting that an electrician had dropped a hot electrode into his shoe.
(Read about one Livelyhood producer's night shift experiences on the road, including hot tub hallucinations!).
Six years later, high school student Randy Gardner attempted to break the Guinness Book of World Records for the longest time awake -- 260 hours. And after 11 days without sleep he suffered no hallucinations or paranoia and no psychotic symptoms.