Compressing five days of work into four can create stress, but the benefits outweigh the downsides, sprawling study shows

July 20, 2025 | 08:00pm

Biggest trial shows four-day work week cuts stress — and workers say it boosts performance

Compressing five days of work into four can create stress, but the benefits outweigh the downsides, sprawling study shows

Workers reported better mental health after they switched to a four-day work week without a reduction in pay. Credit: Getty

Moving to a four-day work week without losing pay leaves employees happier, healthier and higher-performing, according to the largest study of such an intervention so far, encompassing six countries¹. The research showed that a six-month trial of working four days a week reduced burnout, increased job satisfaction and improved mental and physical health.

The study’s authors had wondered whether a condensed working week would add to employees’ stress. “When workers want to deliver the same productivity, they might work very rapidly to get the job done, and their well-being might actually worsen,” says lead author Wen Fan, a sociologist at Boston College in Massachusetts. “But that’s not what we found.” Instead, staff members’ stress levels fell.

The study was published today in Nature Human Behaviour.

Pandemic upheaval

Levels of employee stress and burnout soared during the COVID-19 pandemic, leading many workers to quit their jobs, the authors note. The result was large numbers of unfilled positions in some labour markets.

To see whether shorter weeks might be the antidote for poor morale, researchers launched a study of 2,896 individuals at 141 companies in Australia, New Zealand, the United States, Canada, Ireland and the United Kingdom.

Before making the shift to reduced hours, each company that opted into the overhaul was given roughly eight weeks to restructure its workflow to maintain productivity at 80% of previous workforce hours, purging time-wasting activities such as unnecessary meetings. Two weeks before the trial started, each employee answered a series of questions to evaluate their well-being, including, “Does your work frustrate you?” and “How would you rate your mental health?” After six months on the new schedule, they revisited the same questions.

Overall, workers felt more satisfied with their job performance and reported better mental health after six months of a shortened work week than before it.