healthHealth and Medicine

Forty-Hour Week Is An Hour Too Long For Your Health


Stephen Luntz

Stephen has a science degree with a major in physics, an arts degree with majors in English Literature and History and Philosophy of Science and a Graduate Diploma in Science Communication.

Freelance Writer

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The workers who fought for an 8-hour day knew long hours were bad for their health, but it seems they should have been a little more ambitious. Public domain via wikimedia commons

If working too hard is bad for your mental and physical health, how many hours is too many? The optimum number varies by person, but on average it's best not to work more than 39 hours a week, according to a study published in Social Science and Medicine

There was a time when workers had to strike for the radical idea of a 48-hour working week, subsequently reduced to 40. Yet in more recent decades the trend has reversed, with a mix of paid and unpaid overtime increasing the hours people, at least in the developed world, put into their jobs.


Dr Huong Dinh of the Australian National University set out to measure the effect of this using the Household Income Labour Dynamics of Australia Survey (HILDA). HILDA is a study of almost 8,000 workers examining the work they do in their employment and at home, along with various aspects of their health and well-being. HILDA doesn't just take a snapshot but follows participants through their working lives, making long-term effects visible. Dinh told IFLScience the data allowed the researchers to control for factors such as income, time flexibility, and type of employment contract.

The graph of happiness compared to hours worked looked like an inverted U, Dinh explained. That is, people working too few hours suffered, either from insufficient income or a lack of feeling useful, but those who worked too long had problems as well. Dinh said, there is “a tipping point of 39 hours for an average person, beyond which their mental health starts to decline.”

Naturally work capacity varies with individual factors such as people's need for sleep, but an equally important factor is how much else people have on their plates. A long commute eats away at the time one can spend at work before health effects show up.

In particular, women, who are generally still doing more unpaid housework and childcare, could only average 34 hours of paid work a week before suffering consequences, while the average man could exceed the 39 hours."Given the extra demands placed on women, it's impossible for women to work long hours often expected by employers unless they compromise their health,” Dinh said in a statement. Domestic work was not the only gender-based difference, as women often have roles with less autonomy, which tend to produce more stress.


To anyone who thinks the standard working week is still 9 to 5 and home again, these findings might seem a minor concern, but the researchers point out that two out of every three Australians working full-time jobs are doing more than 40 hours a week, and most nations work longer still.


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