How Many Hours Should You Work per Week?

 

In an article in Fortune magazine Laura Vanderkam wrote that “up until now, there hasn’t been too much data surrounding this question, but researchers at Harvard Business School, the London School of Economics and other institutions have recently begun an ongoing CEO Time Use Project to figure out exactly how work hours relate to success. Using time logs kept by CEOs’ personal assistants, and looking across different cultures, the study asks how CEO time use corresponds with a company’s performance.

 

At this point, data is only available from a group of Italian CEOs of large firms. But according to Harvard’s Raffaella Sadun, ‘we found this very strong correlation between the number of hours spent at work by a CEO and the productivity of the firm’ (defined as revenue per employee) ‘and also the profitability of the firm.’ Every one percentage point rise in hours worked meant firm productivity rose by 2.14 percentage points.

 

Sadun and her colleagues found a big difference in productivity based on how a CEO spent those additional hours. Meeting with employees correlated with more productivity. Meeting with consultants or other outsiders did not. And the Italian CEOs didn’t turn out to be working what many executives would consider a taxing workweek. Each additional hour boosted performance, but that’s not too surprising given that the average CEO in the study was only logging 48 hours per week.

 

Over the last 50 years and beyond the ‘expectations’ around the working day and working week have changed. Thirty years ago the 40 hour week was considered your ‘starting point’, i.e. the absolute minimum you were expected to work – where how you were perceived as an employee would often be based on the amount of time you spent at work and not on ‘your productive output’. Yet even today there are companies that ‘slave drive’ their employees when it comes to work hours, where with an over-supply of labour many employees feel ‘forced’ to work beyond a normal 40/45 hour work week.

 

The other side to the same coin is how much sleep do we need? A common theme in the sleep arena is eight hours sleep a night, but do we really know where this claim came from, or was it just someone splitting the day into eight hours work, eight hours relaxation and family time, and eight hours sleep.

 

Each one of us has a unique sleep requirement. Our sleep need depends upon genetic and physiological factors and also varies by age, sex, and previous sleep amounts. However, a simple definition of sufficient sleep is a sleep duration that is followed by a spontaneous awakening and leaves one feeling refreshed and alert for the day.

 

The National Sleep Foundation in the UK reported that “the relationship between sleep duration, performance and health is important and timely. Between 1959 and 1992 the average amount of sleep reported by middle age individuals decreased by about one hour per night (from 8-9 hours per night to 7-8 hours per night). A study examining the sleep duration from time diaries (records of sleep time and awake time) of full time workers from 1975 to 2006, found a significant increase in the number of individuals who were sleeping less than 6 hours per night. A recent study from the National Health Interview Survey which examined the sleep duration of individuals across several occupations ranging from manufacturing to public administration found that the percent of workers who reported a sleep duration of 6 hours or less per night increased from 24 to 30% in the last 20 years. These findings probably demonstrate the development of widespread partial sleep deprivation or sleep "restriction" which is most likely related to external environmental or social factor(s) such as the need to work more than one job or longer work shifts rather than a biologic change in need for sleep. The important question is the extent to which such changes produce negative consequences for performance, health, and/or quality of life.”

 

Much research investigating sleep duration requirements has examined reduced sleep duration because, as evidenced above, chronic or long-standing sleep restriction is increasingly pervasive in the community. Studies of short sleep duration have shown that this ‘restricted’ sleep can be associated with increased sleepiness, poor performance, and increased health risks or mortality.

 

Organisations and individuals would do well to look at the simple correlation between motivation and output, where by ensuring an employee gets the right balance between work, relaxation and sleep time, you will actually optimise motivation and performance in the work place – or at least you will have the right equation that with the right leadership will ensure optimal healthy organisational performance.

 

For the CEO’s and self-employed, you need to learn to listen to your body and respond to those signals that tell you that you need a break – as ‘burn out’ at the top will lead to other organisational problems that will mean you will have to work even harder. An obvious solution and key competitive advantage is, of course, having the right team around you that will support you and take the pressure off when you are approaching ‘burn out’ and need a break.

 

References:

 

Vanderkam, L. (2011). How many hours should you be working? Fortune Magazine. [On-line: http://fortune.com/2011/06/06/how-many-hours-should-you-be-working/]