Flexible work schedule good for workers' well-being

In today's fast life, our daily schedules often don't match our bodies' natural rhythms. This causes a 'social jetlag' as we lose sleep.

The condition can be a particular problem for shift workers, who work into the night or on a shifting schedule.

"A 'simple' re-organisation of shifts according to chronotype allowed workers to sleep more on workday nights," said Till Roenneberg of the 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," Roenneberg added.

The researchers got the chance to implement their ideas about sleep and work schedules in a real-world factory setting.

The 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.

Morning people were never made to work late and night owls were never forced to get up early for work.

With those adjusted schedules, people felt more satisfied with the sleep they did get and experienced slight improvements in their general well-being.

It also reduced social jetlag - the difference between the midpoint of workers' sleep on work versus free days - by one hour.

While the new findings weren't exactly a surprise, Roenneberg said, it was still "utterly satisfying to find that theory actually works in the real and 'dirty' world".

An earlier report by Roenneberg's team showed a link between social jetlag and obesity, along with other unhealthy habits, including smoking cigarettes and drinking alcohol and caffeine.

"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 Celine Vetter, the first author of the study.

The findings were reported in Current Biology.