The body's circadian rhythm is an alternating cycle of wakefulness and sleep. Normally sleep occurs during a particular phase of the circadian rhythm which occurs at night. Our bodies produce a chemical called melatonin to regulate and promote sleep. When darkness comes, melatonin production rises and we get sleepy. Night shift worker have to fight this and try and stay awake. During the day, they must sleep when their bodies want to be awake. This struggle to adapt to a new circadian rhythm plays havoc with the shift worker. It is unknown whether the body can ever fully adapt to the abnormal cycle.
Night shift workers are slowly and continually sleep deprived. They get, on average, two to four hours less sleep than those who work during the day. The regular sleep disturbances and disruptions shift workers face can lead to severe sleep deprivation, including insomnia.
Consequences of Shift Work
People are most tired between 2 a.m. and 6 a.m., when the body's temperature is at its lowest. And up to 20 percent of shift workers fall asleep on the job regularly, especially in the second half of the shift. Sleepiness affects performance, memory and recall, motor coordination and most certainly mood -- when we're tired, we get irritable.
How serious is sleepiness among shift workers? Insufficient sleep contributed to the Three Mile Island nuclear power plant incident, the Exxon Valdez oil spill and the Space Shuttle Discovery explosion. And more than 100,000 auto accidents each year are related to falling asleep at the wheel.
Many nighttime employees lack time to socialize, attend appointments and run errands. Scheduling differences faced by night workers can lead to feelings of alienation and frustration.
Coping Strategies
Research has shown night owls tend to do better with shift work than morning larks. Younger people tend to adapt easier to varied shifts.
Work Schedules
Studies show it's best to work the same shift. The body is almost never able to adapt to working varying shifts. We know that light affects the ability to sleep soundly so shift workers who get home and hit the bed while it's still dark adapt best.
Taking caffeine during the first half of the shift helps promote alertness throughout the shift. But in the second half of the shift it decreases the amount and quality of sleep after work.
Since the body's clock is programmed by light and dark, exposure to bright light the first half of a night shift helps. Light exposure should end midway through the shift to enhance sleep during the day.
Evidence shows regular breaks and naps on the job can reduce fatigue without hurting performance. In fact, breaks may actually increase productivity and worker satisfaction. And exercise during breaks can improve mood and increase alertness.
If the sun is out when the shift ends, workers should wear wrap-around sunglasses until they're home.
Sleep Schedules
Permanent nightshift employees should maintain the same schedule seven days a week, even on days off work. Converting to a day schedule makes it harder to sleep during the day when returning to work.
People with rotating shifts should think long term. On the last few day shifts, workers should offset their bed times by one to two hours and rise one to two hours later. On the last few days of the evening shift, bedtime and rise time should be delayed by one to two hours. Workers can then begin their night shift schedule already adapted. When reverting back to days, begin to wake up earlier and earlier on the last few night shifts.
On call workers can never by fully prepared for the different schedules they might face. The best advice is to be well rested at all times.
No matter what the work schedule is, naps are almost always a good idea. But some high-stress jobs may be hindered by napping. While naps may increase alertness and performance, they may also contribute to sleep inertia, a tendency to remain at rest up to fifteen minutes after waking. Job demands must be considered before napping. If quick reactions are required, naps may not be a good idea. Naps, whether taken on shift or off shift, must be taken at appropriate times to maximize their benefit.
Shift work is hard enough and sleep schedules shouldn't make it harder.
