Improving Sleep And Performance of Shift Workers

There are more than 22 million Americans who work at times other than the usual “9 to 5" business hours. They are called shift workers, those who work when most people are in bed, and who attempt to sleep when the rest of the world is starting to get up for work.

Shift workers are usually found in hospitals, on police forces, in the transportation and manufacturing industries. They perform critical functions as emergency personnel who meet the demand of global interaction “round-the-clock."

Shift workers don't get enough sleep. Night shift workers have to fight against the natural wake-sleep pattern. Since it's difficult for them to stay alert at night, and equally hard to fall asleep and stay asleep during the day, night shift workers get less sleep, and even if they get sleep, it is usually less restful.

More than just a mere “beauty rest", sleep is essential to the body to help restore and rejuvenate the brain and organ systems for normal function. Lack of sleep may lead to a chronic condition which can be harmful to a person's health, on-the-job safety, task performance, memory, and mood.

In a study at Rush University Medical Center, researchers found that participants who worked a simulated night shift and who were exposed during the wee hours to bright lights for five 15-minute periods became more alert, not immediately but later.

According to one of the researchers, Charmane Eastman, PhD, it wasn't just the lights that helped them. They were also given dark sunglasses to wear on their way home and they went straight to bed at 8:30am.

On the other hand, people in the “control" group who also worked simulated night shifts weren't exposed to bright lights, were given dim but not dark sunglasses, and were allowed unrestricted sleep and all the exposure they wanted to outdoor light.

The study, which involved 24 participants who worked from 11 p.m. to 7 a.m. with two days off, was conducted by Eastman and colleague Mark Smith, a postdoctoral fellow, to try to make the participants' body clocks more normal. They discovered that the bright lights, the dark sunglasses, and enforced sleeping times helped the night workers become more alert and feel less abnormal.

Eastman said that the sunglasses cut out a lot of blue light, “that light in the morning is what keeps real shift workers from adjusting. You go outside, that light tells your body clock it's morning. So the real night shift worker never adjusts. We're tricking the body clock to think night is day and day is night."

The study suggests that light therapy, sunglasses, and strict sleep schedules helped night shift workers create a “compromise circadian phase position," which may result in increased performance and alertness during their night shift while still allowing adequate nighttime sleep on off days. Those in the study's experimental group had black plastic placed over windows.

One important finding is that night shift workers should wake up late on their off days, but no earlier than noon.

In conclusion, the study suggests that light therapy, sunglasses, and strict sleep schedules helped night shift workers create a “compromise circadian phase position," which may result in increased performance and alertness during night shifts while still allowing adequate nighttime sleep on off days.