Companies that have adopted a four-day work week are enjoying significant long-term benefits and won’t be returning to the old way of working, new research has found.

The concept of a four-day work week - where employees receive 100 percent of their pay for working 80 percent of their normal hours while maintaining 100 percent productivity - is picking up steam around the world.

The 4 Day Week Global, a non-profit organisation running trials of the concept and working with governments to form policy, has released the fourth instalment of its research, focusing on the longer-term impact of these trials.

The research involves feedback from 988 people working across 41 companies in the US and Canada who moved to a four-day work week last year.

It’s the first time the non-profit has been able to investigate the impact of a four-day week over 12 months rather than six months.

“Findings are positive across the board, with this new evidence helping to counter concerns that previous successes were down to novelty and couldn’t be sustained long-term,” the report said.

The research found continued improvements in physical and mental wellbeing, along with better productivity, among employees allowed to work a four-day week.

“The 12-month insights are remarkably positive and contribute to building a robust body of evidence showcasing the enduring positive effects of reduced work time,” 4 Day Week Global founders Charlotte Lockhart and Andrew Barnes said in the report.

“These results demonstrate the continued positive trends in business benefits, health and wellbeing gains, the environmental impacts, providing a strong foundation for the widespread adoption of a four-day week.”

The research found that initial reductions in burnout seen following the adoption of a four-day work week were largely sustained after 12 months, while self-rated physical and mental health scores continued to improve across the year.

Of the employees surveyed, 95 percent wanted to continue with the concept, just under 70 percent experienced a reduction in burnouts, 40 percent felt less stressed and anxiety dropped for 39 percent of respondents.

Measured on a self-reported scale of one to five, with five being the best score, the mental health of participants in the trial increased from 2.92 before the trial began to 3.42 after one year, while their physical health jumped from 3.05 to 3.41.

There was also a large increase in self-reported productivity among those working a four-day week.

“People are continuing to work more efficiently as opposed to speeding up and cramming the same work into four days rather than five,” the research found.

On the company side of things, participating businesses rated the overall experience very positively, at an average of 8.7 out of 10, with advantages including in attracting new employees and improvements in productivity and performance.

Of the participating companies, revenue increased by 15 percent, while employees were 32 percent less likely to consider leaving their job.

None of the participating companies said they would be going back to a normal five-day week, with 89 percent definitely continuing the four-day week concept, and 11 percent probably doing so.

The findings mirror the experiences of 19 Australian and New Zealand firms which participated in a trial in the second half of 2022.

Employees from these companies who adopted a shorter work week were more satisfied with their jobs, less likely to experience burnout and less likely to take sick and personal days, the trial revealed.

There has been significant movement towards more widespread adoption of the four-day work week in Australia, with a Senate Committee earlier this year recommending a significant pilot program of the concept in the public service.

Government and Greens Senators backed the call, saying they had heard “substantial evidence” of its effectiveness.