Why a 4-Day Workweek Might Be Better for Your Physical and Mental Health

The results of the world’s largest experiment on a four-day workweek are in, and they show that shorter workweeks might be the antidote to the rising rates of work-related stress and burnout people have been experiencing throughout the pandemic. 

The findings come from the United Kingdom's Four-Day Week Pilot—a trial program that included 61 companies and about 2,900 workers in the U.K., that took place between July and December 2022.

When workers shifted to four-day workweeks (typically Monday through Thursday, while still earning full pay), they experienced measurable reductions in their levels of burnout, stress, anxiety, fatigue, and sleep problems by the end of the six-month trial, researchers found.

And it wasn’t just employees who reaped the benefits: Many companies that participated in the pilot program saw increases in revenue and lower levels in staff turnover—and 92% of the companies that took part in the program plan to continue with the four-day workweek, even though the trial is now over.

Here’s a closer look at the potential health benefits of a four-day workweek and what needs to happen to make three-day weekends a permanent fixture in the lives of workers.

Health Benefits of a 4-Day Workweek

Improvements to workers’ mental health emerged as one of the most prominent benefits from the U.K.’s Four-Day Work Week Pilot. Participants’ mental health scores increased from an average of 2.95 to 3.32 on a five-point scale, some 54% reported a reduction in negative emotions, and their rates of anxiety also fell from 2.26 to 1.96 out of a maximum of four points.

Stress reduction is perhaps the health benefit most closely tied with a four-day workweek. Almost 40% of workers in the recent trial were less stressed after cutting back on work hours. A similar four-day workweek pilot that involved 903 workers primarily in Ireland and the U.S. in 2022 showed similar results, with nearly a third of participants reporting lower frequencies of work-related stress.

Dale Whelehan, PhD, a behavioral scientist and chief executive officer of the non-profit 4 Day Week Global, said that these results show that shorter workweeks may be a powerful health intervention for workers. 

“The interventions we’ve had to date [like] yoga classes at lunchtime and mandatory mental health talks aren’t making any dent in moving the dial toward positive mental health and well-being, but with reduced working hours, we’ve seen significant reductions in stress,” Whelehan told Health.

Over the short-term, four-day workweeks make a positive impact on physical health, as well. At least a third of participants in both of the recent studies reported an improvement in physical health. Sleep problems declined for 40% of workers in the U.K. program and almost as many (37%) in the previous trial. And the amount of sick time and personal days workers used also fell by 65% in the most recent research.

It’s too early to say whether four-day workweeks could lead to long-term health improvements. However, given that chronic stress increases the risk of serious health problems, including heart disease, stroke, and high blood pressure, it’s possible that cutting back on working hours could make lifelong impacts on the health of workers. 

Increased Productivity, Decreased Burnout

Four-day workweeks not only can improve people’s lives outside of the workplace—they also seem to make a difference in their on-the-job performance. A whopping 71% of the participants in the U.K.’s four-day workweek study reported lower levels of burnout, an uptick from the 67% who experienced reduced burnout in the previous study.

It’s worth noting that these four-day workweek trials typically involved two months of preparation at the participating companies (including workshops, coaching, and mentoring) before the workweek was shortened. And in most cases, workers were expected to maintain the same level of productivity they had achieved in a longer workweek, undoubtedly requiring them to become more strategic and efficient while on the job.

This higher level of transparency at work may have contributed to some of the health and productivity benefits that emerged from a shorter workweek, said Michael A. Carollo, PsyD, clinical psychologist and assistant professor of medical psychology at Columbia University Irving Medical Center. 

“Ambiguity and lack of clearly defined expectations can lead to increases in stress, anxiety, and attempts by the employee to fill in gaps that seem important, but maybe aren’t, which leads to feelings of burnout and disconnection,” Carollo told Health. “Increased intentionality and clear expectations always improve anxiety and stress and lead to a higher sense of empowerment and consistency.”

Extra time to recharge may have also played a role in workers’ ability to meet their employers’ productivity expectations in a shorter workweek, said Whelehan.

“Science has shown that cognitive levels of fatigue are reached after about 3.5 hours of work per day, and that’s being generous,” Whelehan said. “Our brain has a finite amount of capacity to function in any given day, so if you want to get the most out of it, you need to stop using your brain for work after a certain point to make sure you get the maximum amount of output the day after.”

He added: “The idea is that you work small amounts, but you rest a lot. That equation should mean that you have loads of energy for your work when you need to do it.”

The theory held true in the most recent trial. Satisfied with workers’ productivity, nearly all of the participating companies said they planned to keep four-day workweeks in place for the foreseeable future, or even permanently.

Popularity and Challenges of 4-Day Workweeks

It’s no surprise that three-day weekends have been popular with workers. In fact, 15% of employees in the U.K. experiment said that no amount of money would convince them to switch back to a five-day workweek schedule.

Four-day workweeks are also becoming a compelling recruitment and retention tool for companies who are struggling to compete for workers amid a shrinking labor pool in recent years. Kickstarter, for example, has found that implementing a four-day workweek has enabled its staff “to live brighter, fuller lives”—a unique benefit an employee may not want to give up for a new job.

There’s also been a push from governments to reduce workers’ hours on the job. In early 2023, Maryland lawmakers introduced a bill with incentives for employers to adopt a four-day workweek. Less than a year prior, California lawmakers began considering a bill that would require some employers to start paying overtime after a worker puts in 32 hours a week, rather than the traditional 40, which could lead to shorter workweeks for many.

But despite its clear-cut benefits and appeal, the four-day workweek comes with certain challenges.

“We find a lot of connection to work, and for individuals with anxiety or a depressive disorder, I wonder if a four-day workweek might increase isolation or disconnection from people,” said Carollo. 

And closing down for a full day each week isn’t doable for certain employers, such as a hospital, so they may need to increase their staff before they can meaningfully reduce their workers’ hours—not an easy feat, given the shortages of health care workers. 

However, Whelehan noted that the four-day workweek may actually be one potential solution to these and other labor issues. He notes that part of the reason healthcare workers in particular are leaving their jobs is due to the long hours and burning out.

“So the four-day workweek is actually the radical solution,” said Whelehan. “By offering reduced working hours, we can actually retain staff and bump up our workforce numbers. You can reduce burnout and absenteeism.”

Looking ahead, Whelehan expects that conversations about four-day workweeks will be normalized within many companies by the end of the year.

“While it was seen as a fringe conversation last year, four-day workweeks are becoming a normal conversation for HR departments and people who want to join companies to ask recruiters,” he said. “The ‘Great Resignation’ has brought the need for many organizations to think of the ‘Great Reimagining’ of their workforce.”