Researchers note that many of us are walking around in a fog caused by “social jet lag,” which happens when we lose sleep because our daily schedules don’t match our bodies’ natural rhythms.
This can be a particular problem for shift workers, who work into the night or on a shifting schedule, researchers said in the study, which was published in the Cell Press journal Current Biology.
“A simple re-organization of shifts according to chronotype allowed workers to sleep more on workday nights,” said Till Roenneberg, Ph.D., of Ludwig-Maximilian-University in Germany.
“As a consequence, they were also able to sleep less on their free days due to a decreased need for compensating an accumulating sleep loss. This is a double-win situation.”
Such a change might have other long-term health implications, too, although that remains to be seen, the researchers noted. An earlier study by the same research team showed a link between social jet lag and obesity, along with other unhealthy habits, including smoking cigarettes and drinking alcohol and caffeine.
The researchers got the chance to implement their theories about sleep and work schedules in a real-world factory setting thanks to a former labor director at ThyssenKrupp Steel Europe. He was interested in finding ways to improve workers’ health and lower their stress.
Factory workers were assigned to an early, late, or intermediate chronotype based on their normal sleep patterns. The researchers then implemented a chronotype-adjusted (CTA) shift schedule.
People with chronotypes on either extreme weren’t assigned to the shift that would be the most challenging for them. For example, morning people were never made to work late and night owls were never forced to get up early for work. Those with an intermediate chronotype served as the control group.
With the new schedule in place, the researchers watched what happened to the workers’ sleep duration and quality, social jet lag, well-being, subjective stress perception, and satisfaction with leisure time.
With the adjusted schedules, people felt more satisfied with the sleep they did get and experienced slight improvements in their general well-being, according to the study’s findings. It also reduced social jet lag — the difference between the midpoint of workers’ sleep on work versus free days — by one hour.
The study found that the improvements were not as great for those who naturally prefer to stay up late, which shows that night work is hard on everyone. After all, even people who like to stay up late aren’t nocturnal, Roenneberg said.
While the new findings weren’t a surprise, Roenneberg said it was “utterly satisfying to find that theory actually works in the real and dirty world. In so many cases it doesn’t.”
The findings also show that flexible work schedules aren’t just more convenient, they can make a difference in the way we feel, and perhaps for our long-term health.
“We know that sleep has important implications not only on physical health but also on mood, stress, and social interactions, so that improving sleep will most probably result in many other positive side effects,” said Céline Vetter, Ph.D., the first author of the study.
Source: Cell Press