In an era of burnout, back-to-back meetings, and blurred work-life boundaries, one solution appears to be gaining undeniable traction—the four-day workweek. Now, one of the largest and most rigorous global studies on this subject has confirmed what many workers have long suspected, a shorter workweek can significantly boost employee well-being without compromising pay. The multi-country research, led by academics from Boston College and University College Dublin and published in Nature Human Behaviour, tracked nearly 3000 workers across 141 companies that trialled a four-day week between 2022 and 2024. Spanning six nations, which included the US, UK, Australia, New Zealand, Canada and Ireland, the study found that reducing the standard workweek from five to four days led to measurable improvements in burnout, job satisfaction, mental health, and even physical health. Notably, the trials required no reduction in pay, offering staff 100 per cent of their regular income for 80 per cent of their work hours.
Real reductions, real results
Companies participating in the trial reduced average work hours from 39 to just over 34 per week, and individual workers followed suit. By comparison, a control group of 12 firms that did not take part in the trial saw no change in hours, and no improvement in well-being. The researchers observed that employees in trial companies reported significantly lower levels of burnout (down 16 per cent) and higher job satisfaction (up 7 per cent). Mental health scores improved by 13 per cent, while physical health rose by 9 per cent. These figures stood in sharp contrast to the control group, which reported no meaningful changes across any metric. Co-author Dr Wen Fan, a sociologist at Boston College, described the results as “a breakthrough in how we think about the future of work.”
More than just time off
But the study goes beyond mere timekeeping. It identifies the key reasons why fewer working hours lead to better outcomes. Three powerful forces emerged as consistent mediators. Improved sleep quality, reduced fatigue, and increased work ability, which means how capable employees feel at doing their jobs well. “What’s striking is that this wasn’t just about taking Fridays off,” noted co-author Dr Juliet Schor. “These companies actively reorganised their work processes, eliminated wasteful practices like unnecessary meetings, and restructured how teams collaborated.” That internal transformation, the study shows, not only allowed for the shorter schedule but also reshaped how employees felt about their work. Many reported feeling more focused, more autonomous, and better connected to colleagues, even with less time spent on the job.
Bigger cuts, bigger benefits
The research also confirmed a “dose-response” effect, where the more hours an individual worker cut from their schedule, the greater their well-being gains. Employees who reduced their hours by eight or more each week saw the sharpest improvements in mental and physical health, burnout, and sleep quality. Even smaller cuts of one to four hours produced measurable benefits, though to a lesser extent. At the company level, however, the relationship was more nuanced. While all organisations that trimmed hours saw well-being gains among staff, larger reductions at the organisational level didn’t always translate into proportionately larger improvements. This suggests that personal control over time may be more important than company-wide scheduling alone.
Rewriting the rules of work
The trials were organised by 4 Day Week Global, a non-profit advocacy group, and implemented by a range of private-sector companies, from marketing firms to manufacturing, education to finance.
While most participating businesses came from high-income English-speaking countries, the implications of the research are far broader. “What we’re really seeing here is a reimagining of work norms that have held firm for more than a century,” said Schor. That reimagination may be necessary. The study highlights how work-related stress and burnout reached record highs during the COVID-19 pandemic. The move to remote work gave many employees a taste of flexibility, but also revealed how broken many conventional work models were. By giving workers more control over their schedules without sacrificing income, the four-day workweek could help resolve long-standing issues of overwork, presenteeism, and mental health neglect.
Not a silver bullet — yet
Still, the researchers caution against overgeneralising. The companies that signed up for the trials tended to be progressive, agile, and already open to innovation. Many were small to mid-sized, limiting how well the results apply to larger or more traditional workplaces. Further, this was not a randomised trial. Participating companies opted in, and many of their employees were already inclined toward flexible work arrangements. Nonetheless, the researchers argue the results are robust, with benefits persisting even a year after the trial began. “There is still work to be done,” said Dr Orla Kelly of University College Dublin, another co-author. “But the evidence is mounting that reducing work hours, when done properly, can be a powerful tool to improve workers’ lives, and sustain productivity.”
The road ahead
With labour shortages, declining engagement, and growing calls for better work-life balance, the momentum for shorter weeks is building. And as this latest study shows, it’s no longer just a utopian ideal. For many, it’s becoming a practical, evidence-based path to healthier, happier, and more sustainable work.
