Many of us feel that we’re working too much—and that’s particularly true for physicians. And, the percentage of physicians who are burned out increases with the number of hours they are working, according to 2019 survey data cited by the American Medical Association. Of doctors working more than 71 hours per week, 57% reported being burned out; of those working 51-60 hours, 48% reported burnout; and for doctors working 41-50 hours per week, 40% reported burnout. 

The long hours come with a cost—affecting physical and mental health, sleep, eating habits, and more. So how many hours should you be working for optimal health? Here’s what the research says. 

Working hours and physical health

Working long hours can leave us feeling tired and off-balance, but evidence suggests being overworked can also affect us physiologically. An analysis published in the International Journal of Environmental Research and Public Health (IJERPH) examined findings from 46 studies between 1998-2018 to explore the health impacts of long working hours.

Among their findings was an association between long work weeks and cardiovascular and cerebrovascular diseases—although the results were a mixed bag.

The authors wrote:

“A U-shaped relationship between the risk of suffering from myocardial infarction and working hours for Japanese workers was found. Those working less than 7 h per day or more than 11 h per day were at greater risk of experiencing myocardial infarction than with those working 7 to 11 h.”

Further, the authors noted:

"One study found that workers in Europe, Japan, Korea, and China who work more than 50 h per week had an increased risk of cerebrocardiovascular diseases, myocardial infarction, and coronary heart disease.”

However, the authors added,

“Some findings differ from such results in that working more than 50 h per week decreased the risk of ischemic heart diseases and myocardial infarction. The results for working hours and cardiovascular and cerebrovascular diseases are not entirely agreed [upon] yet.”

The researchers also found evidence to show that working long hours is associated with increased risks of type 2 diabetes, possibly due to not having enough time to practice healthy eating habits. On the subject of habits, the authors found that working more than 34 hours a week increased the likelihood of workers smoking, drinking alcohol, and not getting enough exercise.

Excessive work may also increase rates of occupational injury, particularly for those working more than 12 hours a day or more than 60 hours a week.

“Long working hours were shown to adversely affect the occupational health of workers,” the authors wrote. “The management on safeguarding the occupational health of workers working long hours should be reinforced.” 

Working hours and sleep

Working too many hours can interfere with sleep, and that can lead to dangerous consequences for physicians. The importance of getting enough sleep is examined in a review published in Nature and Science of Sleep.

The authors noted that insufficient sleep at night is not only associated with fatigue, depression, and poor daytime functioning, but with health problems including obesity, type 2 diabetes, hypertension, cardiovascular disease, and all-cause mortality, as well as safety concerns.

While the research didn’t offer a definitive number of sleep hours for health, the authors concluded that people should get as much sleep as needed to optimise personal health outcomes (cognitive function, mental health, performance, physical health, quality of life). Typically, this means getting somewhere around the hours recommended by public health authorities, the authors noted.

The authors of the IJERPH review wrote that 7 to 8 hours of sleep a night can lower the risk of acute myocardial infarction, cerebrocardiovascular diseases, diabetes, and high blood pressure—and can reduce workplace injuries and mistakes.

Working hours and mental health

When it comes to work and mental health, evidence suggests that finding a middle ground is most beneficial. While we can get certain psychological boosts from working, too much work can result in poor mental health outcomes. 

According to the IJERPH review, studies have found associations between working long hours and conditions like depression and anxiety. One such study examined the impacts of long working hours on depression symptoms in Japanese residents and found that “compared with the residents working less than 60 h per week, those working 80 to 99.9 h per week and more than 99.9 h per week had a 2.83 and 6.96, respectively, greater risk of experiencing depression.” 

Further, the review also cites other studies suggesting that long work weeks contribute to psychological and work stress, particularly for those working 10 or more hours per day, or 40 or more overtime hours per month.

That said, research indicates that working a paid job can offer psychological benefits. According to a study published in Social Science & Medicine, having a job can be conducive to mental well-being, due to structured routines, social contact, and having shared goals with others. The study notes that several analyses have linked unemployment to negative health and well-being outcomes, like psychological distress, anxiety, and reduced happiness.

However, when it comes to the optimal working hours for mental health benefits, the study’s findings suggest that the number of working hours needed to avoid poor outcomes may be quite low. Researchers found that working just 8 hours a week is enough to improve psychological well-being, and that these improvements are similar for those working up to 48 hours a week. Working any more than this was associated with negative consequences to health and well-being, due to exhaustion, burnout, occupational stress, and having less time for self-care.

Overall, the evidence suggests that for optimal physical and mental health, you should temper the amount of overtime you’re working and ensure that you’re getting at least 7 hours of sleep a night. 

This article was originally published on 20th March 2021.

This story is contributed by Alistair Gardiner and is a part of our Global Content Initiative, where we feature selected stories from our Global network which we believe would be most useful and informative to our doctor members.