Nearly three-quarters of the companies that participated in a trial of the four-day work week won’t be returning to the traditional way of working, with a study finding substantial health and wellbeing benefits without any impact on revenue or productivity.

The concept of the 100:80:100 four-day working week, where employees receive the same level of pay for working 80 per cent of their normal hours while maintaining 100 per cent productivity, has picked up steam around the world in the wake of the changes brought on by the COVID-19 pandemic.

The workplace trend has been hailed for improving the mental and physical health of employees, freeing up time for other activities, and boosting productivity and retention for businesses.

The 4 Day Week Global organisation has run trials of the four-day working week around the world, with detailed reports produced following the conclusion of these pilots.

The latest is on 45 German companies which took part in a six-month trial of the four-day work week earlier this year.

The study found most participating companies do not plan to return to a full five-day work week after significant improvements to the physical health and mental wellbeing of employees were identified, without any decline in revenue or profits.

“The trial revealed positive effects on mental health, work-life balance and overall life satisfaction, driven by the additional personal time gained from a shorter work week,” the report said.

Stress down, health up

The study, conducted by the University of Munster and German consulting firm Intraprenor, used hair samples from participants to measure the level of cortisol, a hormone released in response to stress, along with exercise and sleep data captured by smartwatches.

It found significant improvements in mental and physical health for those working a shorter week, compared to a control group working a normal five-day week.

Those who worked the shorter week took more steps each day and were more physically active compared to those who did not, and slept an extra 38 minutes each night on average.

Significantly fewer stress minutes per week were recorded by participants too, equating to an average of 89 fewer minutes.

This means that even though these workers were effectively trying to condense their five-day work week into four days, they still felt less stressed at work and outside of it.

“This suggests that shorter working hours contribute to lowering perceived stress levels,” the report said.

“Interestingly, this finding contrasts with the expectation that having the same workload to complete in less time might lead to an increased subjective perception of stress.

“While the pace of work does appear to increase, this does not correspond to higher stress levels.

“Instead, a market reduction in stress is observed.”

Of the participants in the trial, half said that it contributed to their overall wellbeing either a lot or quite a bit, while 13 per cent said it did somewhat.

Just over 30 per cent said participating in the trial had no impact on their health at all.

Of the participating organisations, around 40 per cent have introduced a permanent four-day work week, while 34 per cent have extended the trial for a longer period.

Success around the world

The report echoes many of the findings of similar trials in Australia, the US and Canada. Nineteen companies from Australia and New Zealand took part in a six-month trial which saw their employees more satisfied with their jobs, less likely to experience burnout and less likely to take sick or personal days.

A growing number of Australian organisations are embracing the new workplace concept, including Medibank and the ACT government, which announced a trial of the concept in the public service earlier this year.

A federal Senate Committee led by government and Greens Senators also last year recommended that a trial be conducted in the public service after they heard “substantial evidence” of its benefits.